Finite Group Databasebeta
Cayley diagram

C2×Dic9 #610

order72
isoclinismisoclinic class of D9
automorphismAut(G) = D4×AGL(1,ℤ/9) (order 432) · Inn(G) = D9 · Out(G) = C3×D4
holomorphG ⋊ Aut(G) = #72220184
homologyAbelianization (H1) = C2×C4 · Schur multiplier (H2) = C2

Aliases

direct productC2×Dic9
unambiguous semidirect product(C2×C9)⋊C4

Splittings

derived, SylowC9 ⋊ C2×C4

Subgroups

subgroupG/H
center, hypercenterC22D9
commutator, hypocenterC9C2×C4
FrattiniC2×C3C2×D3
FittingC22×C9C2
socle, prime radicalC22×C3D3
cosocleC2×C9C22
LCSG ▷ C9
UCSC1 ◁ C22

24 conjugacy classes of subgroups.

Full subgroup data →

Presentation

minimal degreeμ(G) = 15
transitive degreeμt(G) = 72

A minimal faithful permutation representation — 2 generators on 15 points:

(1,2)(3,4,5,6)(8,10)(9,13)(11,12)(14,15);(1,2)(7,15,10,13,12,11,9,8,14)

Conjugacy classes & character table

24 conjugacy classes — view the full character table.

Relationships

maximal subgroup ofC4×Dic9, Dic9⋊C4, C4⋊Dic9, …
maximal normal subgroup ofC4×Dic9, Dic9⋊C4, C4⋊Dic9, …
maximal quotient ofC2×C9⋊C8, #3667, C4×Dic9, …

GAP

Construct this group in GAP via the SmallGroups library:

gap> SmallGroup(72, 7);