Finite Group Databasebeta

← C2×#31296 #7504311

Subgroups — C2×#31296 #7504311

Order 512.

2498 conjugacy classes of subgroups.

The subgroup lattice has 759 nodes — too large to display as a diagram.

Conjugacy classes of subgroups

#subgroupG/Hclass sizemultiplicitynormal?properties
1C2×#2495C211yesmaximal, characteristic, complemented
2C2×#2436C211yesmaximal, characteristic
3#31296C2116yesmaximal, direct product factor
4C2×#2097C211yesmaximal, characteristic, complemented
5C2×#2066C211yesmaximal, characteristic, complemented
6C2×#2042C211yesmaximal, characteristic, complemented
7C2×#2042C211yesmaximal, characteristic, complemented
8C2×#2034C211yesmaximal, characteristic
9C2×#2033C211yesmaximal, characteristic
10C2×#1983C211yesmaximal, characteristic, complemented
11C2×#1958C211yesmaximal, characteristic, complemented
12C2×#1933C211yesmaximal, characteristic, complemented
13C2×#1928C211yesmaximal, characteristic, complemented
14C2×#1923C211yesmaximal, characteristic, complemented
15C2×#1787C211yesmaximal, characteristic, complemented
16C2×#1787C211yesmaximal, characteristic, complemented
17C24×Q8C2211yescharacteristic
18C22×#124C2211yescharacteristic
19C22×#124C2211yescharacteristic
20C22×#121C2211yescharacteristic
21C22×#107C2211yescharacteristic
22C22×#106C2211yescharacteristic
23C22×C4⋊C8C2211yescharacteristic
24C22×#103C2211yescharacteristic
25C22×#103C2211yescharacteristic
26C22×#103C2211yescharacteristic
27C22×#103C2211yescharacteristic
28C22×#103C2211yescharacteristic
29C22×#103C2211yescharacteristic
30C22×#103C2211yescharacteristic
31C22×#103C2211yescharacteristic
32C22×#102C2211yescharacteristic
33C22×#102C2211yescharacteristic
34C22×#102C2211yescharacteristic
35C22×#102C2211yescharacteristic
36C22×C22⋊C8C2211yescharacteristic
37C22×C22⋊C8C2211yescharacteristic
38C22×C4×C8C2211yescharacteristic
39#2495—24no—
40#2495C2218yescomplemented
41#2436—24no—
42#2436C2218yes—
43C2×#400—21no—
44C2×#397—21no—
45C2×#393—21no—
46C2×#393—21no—
47C2×#391C2211yescharacteristic
48C2×#391C2211yescharacteristic
49C2×#389C2211yescharacteristic
50C2×#389C2211yescharacteristic
51C2×#388—21no—
52C2×#386—21no—
53C2×#386—21no—
54C2×#383—21no—
55C2×#382C2211yescharacteristic
56C2×#380C2211yescharacteristic
57C2×#380C2211yescharacteristic
58C2×C4×C4⋊C4C2211yescharacteristic
59C2×C4×C22⋊C4C2211yescharacteristic
60#2097C2218yescomplemented
61#2066C2218yescomplemented
62#2042C2218yescomplemented
63#2042C2218yescomplemented
64#2034C2218yes—
65#2033C2218yes—
66#1983C2218yescomplemented
67#1958C2218yescomplemented
68#1933C2218yescomplemented
69#1928C2218yescomplemented
70#1923C2218yescomplemented
71#1787C2218yescomplemented
72#1787C2218yescomplemented
73C2×#340C2211yescharacteristic
74C2×#340C2211yescharacteristic
75C2×#336C2211yescharacteristic
76C2×#336C2211yescharacteristic
77C23×Q8—21no—
78C23×Q8—22no—
79C23×Q8—24no—
80C23×Q8—24no—
81C23×Q8—42no—
82C23×Q8—42no—
83C23×Q8—42no—
84C23×Q8—42no—
85C23×Q8C2311yescharacteristic
86C23×Q8C2311yescharacteristic
87C23×Q8C2314yes—
88C23×D4—21no—
89C23×D4C2311yescharacteristic
90C24×C4—21no—
91C24×C4C2311yescharacteristic
92C23×C8C2311yescharacteristic
93C23×C8C2311yescharacteristic
94C23×C8C2311yescharacteristic
95C23×C8C2311yescharacteristic
96C2×#124—24no—
97C2×#124—24no—
98C2×#124—22no—
99C2×#124—22no—
100C2×#124—42no—
101C2×#124—42no—
102C2×#124C2314yes—
103C2×#124C2314yes—
104C2×#121—22no—
105C2×#121—42no—
106C2×#121—42no—
107C2×#121C2314yes—
108C22×C4⋊C4—21no—
109C22×C4⋊C4—21no—
110C22×C4⋊C4C2311yescharacteristic
111C22×C4⋊C4C2311yescharacteristic
112C22×C4⋊C4C2311yescharacteristic
113C22×C4⋊C4C2311yescharacteristic
114C22×C4⋊C4C2311yescharacteristic
115C22×C22⋊C4—21no—
116C22×C22⋊C4—21no—
117C22×C22⋊C4—21no—
118C22×C22⋊C4—21no—
119C22×C22⋊C4—21no—
120C22×C22⋊C4—21no—
121C22×C22⋊C4—21no—
122C22×C22⋊C4D411yescharacteristic
123C22×C22⋊C4D411yescharacteristic
124C22×C42—21no—
125C22×C42C2311yescharacteristic
126C22×C42C2311yescharacteristic
127C2×#107—42no—
128C2×#107C2314yes—
129C2×#106—42no—
130C2×#106C2314yes—
131C2×C4⋊C8—42no—
132C2×C4⋊C8C2314yes—
133C2×#103—24no—
134C2×#103—24no—
135C2×#103—42no—
136C2×#103—42no—
137C2×#103—42no—
138C2×#103—42no—
139C2×#103—42no—
140C2×#103—42no—
141C2×#103C2314yes—
142C2×#103C2314yes—
143C2×#103C2314yes—
144C2×#103C2314yes—
145C2×#103C2314yes—
146C2×#103C2314yes—
147C2×#103C2314yes—
148C2×#103C2314yes—
149C2×#102—42no—
150C2×#102—42no—
151C2×#102—42no—
152C2×#102—42no—
153C2×#102C2314yes—
154C2×#102C2314yes—
155C2×#102C2314yes—
156C2×#102C2314yes—
157C2×C22⋊C8—42no—
158C2×C22⋊C8—42no—
159C2×C22⋊C8C2314yes—
160C2×C22⋊C8C2314yes—
161C2×C4×C8—42no—
162C2×C4×C8C2314yes—
163#400—28no—
164#397—28no—
165#393—28no—
166#393—28no—
167#391—22no—
168#391—22no—
169#391C2314yes—
170#391C2314yes—
171#389—22no—
172#389—22no—
173#389C2314yes—
174#389C2314yes—
175#388—28no—
176#386—28no—
177#386—28no—
178#383—28no—
179#382—22no—
180#382C2314yes—
181#380—22no—
182#380—22no—
183#380C2314yes—
184#380C2314yes—
185C4×C4⋊C4—22no—
186C4×C4⋊C4C2314yes—
187C4×C22⋊C4D414yes—
188C4×C22⋊C4C2314yes—
189C2×#95—21no—
190C2×#95—21no—
191C2×#95—21no—
192C2×#95—21no—
193C2×#95—21no—
194C2×#95—21no—
195C2×#95—21no—
196C2×#95—21no—
197C2×#95—21no—
198C2×#95—21no—
199C2×#95—21no—
200C2×#95D411yescharacteristic
201C2×#95D411yescharacteristic
202#340C2314yes—
203#340C2314yes—
204#336C2314yes—
205#336C2314yes—
206C25—21no—
207C25C2×D411yescharacteristic
208C22×Q8—21no—
209C22×Q8—21no—
210C22×Q8—24no—
211C22×Q8—22no—
212C22×Q8—22no—
213C22×Q8—28no—
214C22×Q8—28no—
215C22×Q8—22no—
216C22×Q8—22no—
217C22×Q8—22no—
218C22×Q8—22no—
219C22×Q8—22no—
220C22×Q8—22no—
221C22×Q8—22no—
222C22×Q8—22no—
223C22×Q8—44no—
224C22×Q8—44no—
225C22×Q8—44no—
226C22×Q8—44no—
227C22×Q8—44no—
228C22×Q8—44no—
229C22×Q8—48no—
230C22×Q8—48no—
231C22×Q8—44no—
232C22×Q8—48no—
233C22×Q8—416no—
234C22×Q8—416no—
235C22×Q8—416no—
236C22×Q8—416no—
237C22×Q8#4114yes—
238C22×Q8#4114yes—
239C22×Q8C2412yes—
240C22×Q8C2412yes—
241C22×D4—24no—
242C22×D4—21no—
243C22×D4—22no—
244C22×D4—22no—
245C22×D4—22no—
246C22×D4—22no—
247C22×D4—22no—
248C22×D4—22no—
249C22×D4—44no—
250C22×D4—44no—
251C22×D4—44no—
252C22×D4C2412yes—
253C23×C4—21no—
254C23×C4—21no—
255C23×C4—22no—
256C23×C4—22no—
257C23×C4—22no—
258C23×C4—22no—
259C23×C4—22no—
260C23×C4—22no—
261C23×C4—24no—
262C23×C4—21no—
263C23×C4—21no—
264C23×C4—21no—
265C23×C4—21no—
266C23×C4—21no—
267C23×C4—44no—
268C23×C4—44no—
269C23×C4—44no—
270C23×C4C2×D412yes—
271C23×C4C2×D411yescharacteristic
272C23×C4C2×D411yescharacteristic
273C23×C4C2×D411yescharacteristic
274C23×C4C2×D411yescharacteristic
275C23×C4C2×D411yescharacteristic
276C23×C4C2412yes—
277C23×C4C2411yescharacteristic
278C22×C8—22no—
279C22×C8—22no—
280C22×C8—22no—
281C22×C8—22no—
282C22×C8—22no—
283C22×C8—22no—
284C22×C8—22no—
285C22×C8—22no—
286C22×C8—22no—
287C22×C8—22no—
288C22×C8—22no—
289C22×C8—22no—
290C22×C8C2412yes—
291C22×C8C2412yes—
292C22×C8C2412yes—
293C22×C8C2412yes—
294#124—28no—
295#124—28no—
296#124—44no—
297#124—44no—
298#124—48no—
299#124—48no—
300#121—44no—
301#121—44no—
302#121—48no—
303C2×C4⋊C4—22no—
304C2×C4⋊C4—22no—
305C2×C4⋊C4—22no—
306C2×C4⋊C4—22no—
307C2×C4⋊C4—22no—
308C2×C4⋊C4—22no—
309C2×C4⋊C4—22no—
310C2×C4⋊C4—22no—
311C2×C4⋊C4—22no—
312C2×C4⋊C4—22no—
313C2×C4⋊C4—21no—
314C2×C4⋊C4—21no—
315C2×C4⋊C4—21no—
316C2×C4⋊C4—21no—
317C2×C4⋊C4—21no—
318C2×C4⋊C4—24no—
319C2×C4⋊C4—24no—
320C2×C4⋊C4—82no—
321C2×C4⋊C4—82no—
322C2×C4⋊C4C2412yes—
323C2×C4⋊C4C2412yes—
324C2×C4⋊C4C2412yes—
325C2×C4⋊C4C2412yes—
326C2×C4⋊C4C2412yes—
327C2×C22⋊C4—24no—
328C2×C22⋊C4—24no—
329C2×C22⋊C4—24no—
330C2×C22⋊C4—24no—
331C2×C22⋊C4—24no—
332C2×C22⋊C4—24no—
333C2×C22⋊C4—24no—
334C2×C22⋊C4—24no—
335C2×C22⋊C4—42no—
336C2×C22⋊C4—44no—
337C2×C22⋊C4—44no—
338C2×C22⋊C4—44no—
339C2×C22⋊C4—44no—
340C2×C22⋊C4—44no—
341C2×C22⋊C4—44no—
342C2×C22⋊C4—82no—
343C2×C22⋊C4C2×D414yes—
344C2×C22⋊C4C2×D414yes—
345C2×C42—22no—
346C2×C42—22no—
347C2×C42—22no—
348C2×C42—22no—
349C2×C42—24no—
350C2×C42—44no—
351C2×C42C2×D412yes—
352C2×C42C2×D412yes—
353C2×C42C2412yes—
354C2×C42C2412yes—
355#107—44no—
356#106—44no—
357C4⋊C8—44no—
358#103—28no—
359#103—28no—
360#103—44no—
361#103—44no—
362#103—44no—
363#103—44no—
364#103—44no—
365#103—44no—
366#102—44no—
367#102—44no—
368#102—44no—
369#102—44no—
370C22⋊C8—44no—
371C22⋊C8—44no—
372C4×C8—44no—
373#95—24no—
374#95—24no—
375#95—24no—
376#95—24no—
377#95—24no—
378#95—24no—
379#95—24no—
380#95—24no—
381#95—24no—
382#95—24no—
383#95—24no—
384#95C2×D414yes—
385#95C2×D414yes—
386C24—22no—
387C24—22no—
388C24—22no—
389C24—22no—
390C24—22no—
391C24—22no—
392C24—22no—
393C24—42no—
394C24—42no—
395C24—42no—
396C24—42no—
397C24—42no—
398C24—42no—
399C24—42no—
400C24#13514yes—
401C24C22×D412yes—
402C24C22×D411yescharacteristic
403C2×Q8—24no—
404C2×Q8—24no—
405C2×Q8—22no—
406C2×Q8—22no—
407C2×Q8—28no—
408C2×Q8—28no—
409C2×Q8—28no—
410C2×Q8—28no—
411C2×Q8—22no—
412C2×Q8—22no—
413C2×Q8—22no—
414C2×Q8—22no—
415C2×Q8—22no—
416C2×Q8—22no—
417C2×Q8—22no—
418C2×Q8—22no—
419C2×Q8—48no—
420C2×Q8—48no—
421C2×Q8—48no—
422C2×Q8—416no—
423C2×Q8—416no—
424C2×Q8—416no—
425C2×Q8—464no—
426C2×Q8—416no—
427C2×Q8—432no—
428C2×Q8—42no—
429C2×Q8—42no—
430C2×Q8—44no—
431C2×Q8—44no—
432C2×Q8—42no—
433C2×Q8—42no—
434C2×Q8—44no—
435C2×Q8—44no—
436C2×Q8C2×#4114yes—
437C2×Q8C2×#4114yes—
438C2×D4—22no—
439C2×D4—22no—
440C2×D4—22no—
441C2×D4—22no—
442C2×D4—22no—
443C2×D4—22no—
444C2×D4—48no—
445C2×D4—48no—
446C2×D4—48no—
447C2×D4—42no—
448C2×D4—44no—
449C2×D4—44no—
450C2×D4—42no—
451C2×D4—42no—
452C2×D4—44no—
453C2×D4—44no—
454C2×D4—816no—
455C22×C4—22no—
456C22×C4—22no—
457C22×C4—22no—
458C22×C4—22no—
459C22×C4—22no—
460C22×C4—24no—
461C22×C4—24no—
462C22×C4—22no—
463C22×C4—22no—
464C22×C4—22no—
465C22×C4—22no—
466C22×C4—22no—
467C22×C4—22no—
468C22×C4—22no—
469C22×C4—22no—
470C22×C4—22no—
471C22×C4—22no—
472C22×C4—22no—
473C22×C4—22no—
474C22×C4—24no—
475C22×C4—24no—
476C22×C4—24no—
477C22×C4—22no—
478C22×C4—22no—
479C22×C4—22no—
480C22×C4—22no—
481C22×C4—22no—
482C22×C4—22no—
483C22×C4—22no—
484C22×C4—22no—
485C22×C4—22no—
486C22×C4—22no—
487C22×C4—22no—
488C22×C4—48no—
489C22×C4—48no—
490C22×C4—48no—
491C22×C4—432no—
492C22×C4—42no—
493C22×C4—42no—
494C22×C4—42no—
495C22×C4—42no—
496C22×C4—44no—
497C22×C4—44no—
498C22×C4—44no—
499C22×C4—44no—
500C22×C4—42no—
501C22×C4—42no—
502C22×C4—42no—
503C22×C4—42no—
504C22×C4—42no—
505C22×C4—42no—
506C22×C4—42no—
507C22×C4—42no—
508C22×C4—42no—
509C22×C4—42no—
510C22×C4—42no—
511C22×C4—42no—
512C22×C4—42no—
513C22×C4—42no—
514C22×C4—42no—
515C22×C4C22×D412yes—
516C22×C4C22×D412yes—
517C22×C4C22×D412yes—
518C22×C4C22×D412yes—
519C22×C4C22×D412yes—
520C22×C4C22×D411yescharacteristic
521C22×C4C2×#4112yes—
522C22×C4C2×#4112yes—
523C22×C4H(5,𝔽2)12yes—
524C22×C4H(5,𝔽2)12yes—
525C22×C4H(5,𝔽2)12yes—
526C22×C4H(5,𝔽2)12yes—
527C22×C4C2511yescharacteristic
528C2×C8—22no—
529C2×C8—22no—
530C2×C8—22no—
531C2×C8—22no—
532C2×C8—22no—
533C2×C8—22no—
534C2×C8—22no—
535C2×C8—22no—
536C2×C8—22no—
537C2×C8—22no—
538C2×C8—22no—
539C2×C8—22no—
540C2×C8—44no—
541C2×C8—44no—
542C2×C8—44no—
543C2×C8—44no—
544C4⋊C4—22no—
545C4⋊C4—22no—
546C4⋊C4—22no—
547C4⋊C4—22no—
548C4⋊C4—22no—
549C4⋊C4—22no—
550C4⋊C4—22no—
551C4⋊C4—22no—
552C4⋊C4—22no—
553C4⋊C4—22no—
554C4⋊C4—42no—
555C4⋊C4—42no—
556C4⋊C4—42no—
557C4⋊C4—42no—
558C4⋊C4—42no—
559C4⋊C4—84no—
560C4⋊C4—84no—
561C22⋊C4—28no—
562C22⋊C4—44no—
563C22⋊C4—48no—
564C22⋊C4—48no—
565C22⋊C4—48no—
566C22⋊C4—48no—
567C22⋊C4—48no—
568C22⋊C4—48no—
569C22⋊C4—84no—
570C42—24no—
571C42—24no—
572C42—22no—
573C42—22no—
574C42—22no—
575C42—22no—
576C42—48no—
577C23—22no—
578C23—22no—
579C23—22no—
580C23—28no—
581C23—28no—
582C23—28no—
583C23—22no—
584C23—22no—
585C23—22no—
586C23—44no—
587C23—44no—
588C23—44no—
589C23—44no—
590C23—42no—
591C23—42no—
592C23—42no—
593C23—42no—
594C23—42no—
595C23—42no—
596C23—42no—
597C23—84no—
598C23—84no—
599C23—84no—
600C23—84no—
601C23—84no—
602C23—84no—
603C23—84no—
604C23#53512yes—
605C23#54612yes—
606C23#54612yes—
607C23C2×#13514yes—
608C23C2×#13512yes—
609C23#57512yes—
610C23#57712yes—
611C23#57812yes—
612C23C23×D411yescharacteristic
613Q8—24no—
614Q8—24no—
615Q8—24no—
616Q8—24no—
617Q8—432no—
618Q8—42no—
619Q8—42no—
620Q8—48no—
621Q8—48no—
622Q8—42no—
623Q8—42no—
624D4—42no—
625D4—42no—
626D4—42no—
627D4—42no—
628D4—816no—
629D4—84no—
630C2×C4—22no—
631C2×C4—22no—
632C2×C4—22no—
633C2×C4—22no—
634C2×C4—22no—
635C2×C4—24no—
636C2×C4—24no—
637C2×C4—22no—
638C2×C4—22no—
639C2×C4—22no—
640C2×C4—22no—
641C2×C4—22no—
642C2×C4—22no—
643C2×C4—22no—
644C2×C4—22no—
645C2×C4—22no—
646C2×C4—22no—
647C2×C4—432no—
648C2×C4—42no—
649C2×C4—42no—
650C2×C4—44no—
651C2×C4—48no—
652C2×C4—48no—
653C2×C4—42no—
654C2×C4—42no—
655C2×C4—44no—
656C2×C4—44no—
657C2×C4—44no—
658C2×C4—44no—
659C2×C4—42no—
660C2×C4—42no—
661C2×C4—48no—
662C2×C4—42no—
663C2×C4—42no—
664C2×C4—42no—
665C2×C4—42no—
666C2×C4—42no—
667C2×C4—42no—
668C2×C4—42no—
669C2×C4—42no—
670C2×C4—42no—
671C2×C4—42no—
672C2×C4—42no—
673C2×C4—42no—
674C2×C4—42no—
675C2×C4—42no—
676C2×C4—42no—
677C2×C4—42no—
678C2×C4—42no—
679C2×C4—84no—
680C2×C4—84no—
681C2×C4—84no—
682C2×C4—84no—
683C2×C4—84no—
684C2×C4#53512yes—
685C2×C4#53814yes—
686C2×C4#53814yes—
687C2×C4#54612yes—
688C2×C4#54612yes—
689C2×C4#55114yes—
690C2×C4#56014yes—
691C2×C4C22×#4111yescharacteristic
692C2×C4C22×#4111yescharacteristic
693C2×C4C2×H(5,𝔽2)11yescharacteristic
694C2×C4C2×H(5,𝔽2)11yescharacteristic
695C2×C4C2×H(5,𝔽2)11yescharacteristic
696C2×C4C2×H(5,𝔽2)11yescharacteristic
697C8—42no—
698C8—42no—
699C8—42no—
700C8—42no—
701C22—24no—
702C22—24no—
703C22—24no—
704C22—416no—
705C22—42no—
706C22—42no—
707C22—42no—
708C22—42no—
709C22—82no—
710C22—82no—
711C22—82no—
712C22—82no—
713C22—82no—
714C22—82no—
715C22—82no—
716C22—168no—
717C22#268514yes—
718C22#321114yes—
719C22#322514yes—
720C22#330014yes—
721C22#330114yes—
722C22#332114yes—
723C22#332714yes—
724C22C2×#53511yescharacteristic
725C22C2×#54611yescharacteristic
726C22C2×#54611yescharacteristic
727C22C22×#13511yescharacteristic
728C22C2×#57511yescharacteristic
729C22C2×#57711yescharacteristic
730C22C2×#57811yescharacteristic
731C4—42no—
732C4—44no—
733C4—44no—
734C4—42no—
735C4—42no—
736C4—42no—
737C4—42no—
738C4—82no—
739C4—82no—
740C4—82no—
741C4—82no—
742C4—82no—
743C4#268514yes—
744C4C2×#53811yescharacteristic
745C4C2×#53811yescharacteristic
746C4C2×#55111yescharacteristic
747C4C2×#56011yescharacteristic
748C2—44no—
749C2—162no—
750C2#3129618yesdirect product factor
751C2C2×#268511yescharacteristic
752C2C2×#321111yescharacteristic
753C2C2×#322511yescharacteristic
754C2C2×#330011yescharacteristic
755C2C2×#330111yescharacteristic
756C2C2×#332111yescharacteristic
757C2C2×#332711yescharacteristic
subgroupG/H
center, socleC24C22×D4
commutator, Frattini, cosocleC22×C4C25
prime radicalC22×#121C22
LCSG ▷ C22×C4 ▷ C2 ▷ C1
UCSC1 ◁ C24 ◁ C2×C4×C22⋊C4 ◁ G
LECSG ▷ C22×C4 ▷ C2 ▷ C1

Complements

Splittings G = N ⋊ H with N normal; H ≅ G/N.

NH ≅ G/Ntype
1. C2×#2495C2semidirect
3. #31296C2direct (N × H)
4. C2×#2097C2semidirect
5. C2×#2066C2semidirect
6. C2×#2042C2semidirect
7. C2×#2042C2semidirect
10. C2×#1983C2semidirect
11. C2×#1958C2semidirect
12. C2×#1933C2semidirect
13. C2×#1928C2semidirect
14. C2×#1923C2semidirect
15. C2×#1787C2semidirect
16. C2×#1787C2semidirect
40. #2495C22semidirect
60. #2097C22semidirect
61. #2066C22semidirect
62. #2042C22semidirect
63. #2042C22semidirect
66. #1983C22semidirect
67. #1958C22semidirect
68. #1933C22semidirect
69. #1928C22semidirect
70. #1923C22semidirect
71. #1787C22semidirect
72. #1787C22semidirect
750. C2#31296direct (N × H)

Maximal subgroups

By isomorphism type — maximal subgroups of the same type appear once, whether or not they are normal.

subgroupindex
C2×#24952
C2×#24362
#312962
C2×#20972
C2×#20662
C2×#20422
C2×#20342
C2×#20332
C2×#19832
C2×#19582
C2×#19332
C2×#19282
C2×#19232
C2×#17872