Finite Group Databasebeta
Cayley diagram

C2×D9 #152

order36
isoclinismisoclinic class of D9
automorphismAut(G) = C2×AGL(1,ℤ/9) (order 108) · Inn(G) = D9 · Out(G) = C2×C3
holomorphG ⋊ Aut(G) = #72213202
homologyAbelianization (H1) = C22 · Schur multiplier (H2) = C2

Aliases

dihedralD18
direct productC2×D9
unambiguous semidirect productC9⋊C22
unambiguous semidirect product(C2×C9)⋊C2

Splittings

FittingC2×C9 ⋊ C2
derived, SylowC9 ⋊ C22

Subgroups

subgroupG/H
center, hypercenterC2D9
commutator, cosocle, hypocenterC9C22
FrattiniC3C2×D3
FittingC2×C9C2
socleC2×C3D3
LCSG ▷ C9
UCSC1 ◁ C2

15 conjugacy classes of subgroups.

Full subgroup data →

Presentation

minimal degreeμ(G) = 11
transitive degreeμt(G) = 18

A minimal faithful permutation representation — 2 generators on 11 points:

(1,2)(3,4,5,6,7,8,9,10,11);(4,11)(5,10)(6,9)(7,8)

Conjugacy classes & character table

C1C2C3C4C5C6C7C8C9C10C11C12
size122229122229
order139992261818182
χ1111111111111
χ211111-111111-1
χ322-1-1-1022-1-1-10
χ42-1ζ+ζ8ζ2+ζ7ζ4+ζ502-1ζ+ζ8ζ2+ζ7ζ4+ζ50
χ52-1ζ2+ζ7ζ4+ζ5ζ+ζ802-1ζ2+ζ7ζ4+ζ5ζ+ζ80
χ62-1ζ4+ζ5ζ+ζ8ζ2+ζ702-1ζ4+ζ5ζ+ζ8ζ2+ζ70
χ7111111-1-1-1-1-1-1
χ811111-1-1-1-1-1-11
χ922-1-1-10-2-21110
χ102-1ζ+ζ8ζ2+ζ7ζ4+ζ50-21−ζ−ζ8−ζ2−ζ7−ζ4−ζ50
χ112-1ζ2+ζ7ζ4+ζ5ζ+ζ80-21−ζ2−ζ7−ζ4−ζ5−ζ−ζ80
χ122-1ζ4+ζ5ζ+ζ8ζ2+ζ70-21−ζ4−ζ5−ζ−ζ8−ζ2−ζ70

Here ζ is a primitive root of unity of order 9 (ζ9 = 1).

Relationships

maximal subgroup ofC4×D9, D36, #611, …
maximal normal subgroup ofC4×D9, D36, #611, …
maximal quotient ofDic18, C4×D9, D36, …

GAP

Construct this group in GAP via the SmallGroups library:

gap> SmallGroup(36, 4);