Finite Group DatabasebetaFinite Group Databasebeta| order | 640 |
| nilpotency class | 2 |
| isoclinism | isoclinic class of D4 |
| automorphism | ? |
| homology | Abelianization (H1) = C24×C4×C5 · Schur multiplier (H2) = C29 |
| direct product | C22×C5×#131 |
| subgroup | G/H | |
|---|---|---|
| center | C22×C5×C8 | C22 |
| commutator | C2 | C24×C4×C5 |
| Frattini, cosocle | C4 | C25×C5 |
| socle | C23×C5 | C22×C4 |
| prime radical | C22×C5×#41 | C2 |
| LCS | G ▷ C2 ▷ C1 | |
| UCS | C1 ◁ C22×C5×C8 ◁ G | |
1504 conjugacy classes of subgroups; only the 1384 normal subgroups are shown.
This group has 1504 conjugacy classes of subgroups — too many to draw. Only its 1384 normal subgroups are shown.
Dotted edges: containments with no intermediate normal subgroup — omitted non-normal subgroups may lie between.
| minimal degree | μ(G) = 25 |
| transitive degree | μt(G) = 320 |
A minimal faithful permutation representation — 5 generators on 25 points:
(1,2)(21,22,23,24,25);(3,4);(5,6,8,11,9,12,15,18)(7,10,14,17,13,16,19,20);(5,7)(6,10)(8,14)(9,13)(11,17)(12,16)(15,19)(18,20);(7,13)(10,16)(14,19)(17,20)400 conjugacy classes — view the full character table.
Construct this group in GAP via the SmallGroups library:
gap> SmallGroup(640, 21438);