Abstract group 128.2025: $C_2.D_4^2$

• Label: 128.2025
• Order: \( 2^{7} \)
• Exponent: \( 2^{3} \)
• Nilpotent: yes
• Solvable: yes
• $\card{G^{\mathrm{ab}}}$: \( 2^{4} \)
• $\card{Z(G)}$: \( 2 \)
• $\card{\Aut(G)}$: \( 2^{11} \)
• $\card{\mathrm{Out}(G)}$: \( 2^{5} \)
• Perm deg.: $32$
• Trans deg.: $32$
• Rank: $4$

Group information

Description:	$C_2.D_4^2$
Order:	\(128\)\(\medspace = 2^{7} \)
Exponent:	\(8\)\(\medspace = 2^{3} \)
Automorphism group:	$D_8^2.D_4$, of order \(2048\)\(\medspace = 2^{11} \)
Composition factors:	$C_2$ x 7
Nilpotency class:	$3$
Derived length:	$2$

This group is nonabelian, a $p$-group (hence nilpotent, solvable, supersolvable, monomial, elementary, and hyperelementary), and metabelian.

Group statistics

Order	1	2	4	8
Elements	1	19	60	48	128
Conjugacy classes	1	6	12	10	29
Divisions	1	6	12	8	27
Autjugacy classes	1	3	4	3	11

Dimension	1	2	4	8
Irr. complex chars.	16	8	5	0	29
Irr. rational chars.	16	8	1	2	27

Minimal presentations

Permutation degree:	$32$
Transitive degree:	$32$
Rank:	$4$
Inequivalent generating quadruples:	$40320$

Minimal degrees of faithful linear representations

	Over $\mathbb{C}$	Over $\mathbb{R}$	Over $\mathbb{Q}$
Irreducible	4	8	16
Arbitrary	not computed	not computed	not computed

Constructions

Presentation:	$\langle a, b, c, d \mid a^{2}=c^{2}=d^{8}=[a,d]=[b,d]=1, b^{4}=d^{4}, b^{a}=b^{3}, c^{a}=cd^{4}, c^{b}=cd^{4}, d^{c}=d^{7} \rangle$
Permutation group:	Degree $32$ $\langle(1,25,2,26)(3,27,4,28)(5,32,6,31)(7,29,8,30)(9,20,10,19)(11,17,12,18)(13,22,14,21) \!\cdots\! \rangle$
Transitive group:	32T1839				more information
Direct product:	not isomorphic to a non-trivial direct product
Semidirect product:	$(D_4.D_4)$ $\,\rtimes\,$ $C_2$	$(D_4.D_4)$ $\,\rtimes\,$ $C_2$	$(C_8.D_4)$ $\,\rtimes\,$ $C_2$	$(D_8:C_4)$ $\,\rtimes\,$ $C_2$	all 5
Trans. wreath product:	not isomorphic to a non-trivial transitive wreath product
Non-split product:	$D_8$ . $D_4$	$Q_{16}$ . $D_4$	$C_2$ . $D_4^2$	$\SD_{16}$ . $D_4$	all 25

Elements of the group are displayed as words in the presentation generators from the presentation above.

Homology

Abelianization:	$C_{2}^{4} $
Schur multiplier:	$C_{2}^{5}$
Commutator length:	$1$

Subgroups

There are 412 subgroups in 222 conjugacy classes, 92 normal (8 characteristic).

Characteristic subgroups are shown in this color. Normal (but not characteristic) subgroups are shown in this color.

Special subgroups

Center:	$Z \simeq$ $C_2$	$G/Z \simeq$ $D_4^2$
Commutator:	$G' \simeq$ $C_2\times C_4$	$G/G' \simeq$ $C_2^4$
Frattini:	$\Phi \simeq$ $C_2\times C_4$	$G/\Phi \simeq$ $C_2^4$
Fitting:	$\operatorname{Fit} \simeq$ $C_2.D_4^2$	$G/\operatorname{Fit} \simeq$ $C_1$
Radical:	$R \simeq$ $C_2.D_4^2$	$G/R \simeq$ $C_1$
Socle:	$\operatorname{soc} \simeq$ $C_2$	$G/\operatorname{soc} \simeq$ $D_4^2$
2-Sylow subgroup:	$P_{ 2 } \simeq$ $C_2.D_4^2$

Hi

Subgroup diagram and profile

Classes of subgroups up to conjugation

No diagram available: subgroups only stored up to automorphism

Classes of subgroups up to automorphism

Normal subgroups

No diagram available: subgroups only stored up to automorphism

Normal subgroups up to automorphism

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Subgroup information

Click on a subgroup in the diagram to see information about it.

Classes of subgroups up to conjugation

Order 128: $C_2.D_4^2$

Order 64: $D_4.D_4$ x 4, $C_8.D_4$ x 4, $D_4.D_4$ x 4, $D_8:C_4$ x 2, $C_4:Q_{16}$

Order 32: $Q_{16}:C_2$ x 16, $C_2\times Q_{16}$ x 8, $D_8:C_2$ x 6, $C_4.D_4$ x 4, $C_4.C_2^3$ x 4, $\OD_{16}:C_2$ x 4, $C_4\wr C_2$ x 4, $C_4:Q_8$ x 2, $C_8.C_4$ x 2, $C_4\times C_8$

Order 16: $Q_{16}$ x 18, $D_4:C_2$ x 16, $\SD_{16}$ x 12, $C_2\times Q_8$ x 12, $\OD_{16}$ x 8, $C_2\times C_8$ x 6, $D_8$ x 2, $C_4:C_4$ x 2, $C_4^2$

Order 8: $C_2\times C_4$ x 18, $Q_8$ x 16, $D_4$ x 12, $C_8$ x 8

Order 4: $C_4$ x 12, $C_2^2$ x 5

Order 2: $C_2$ x 6

Order 1: $C_1$

Classes of subgroups up to automorphism

Order 128: $C_2.D_4^2$

Order 64: $D_4.D_4$, $C_4:Q_{16}$, $C_8.D_4$, $D_4.D_4$, $D_8:C_4$

Order 32: $Q_{16}:C_2$ x 2, $D_8:C_2$ x 2, $C_2\times Q_{16}$ x 2, $C_4.D_4$, $C_4.C_2^3$, $\OD_{16}:C_2$, $C_4:Q_8$, $C_4\times C_8$, $C_8.C_4$, $C_4\wr C_2$

Order 16: $Q_{16}$ x 4, $D_4:C_2$ x 3, $\SD_{16}$ x 2, $\OD_{16}$ x 2, $C_2\times C_8$ x 2, $C_2\times Q_8$ x 2, $D_8$, $C_4:C_4$, $C_4^2$

Order 8: $C_2\times C_4$ x 5, $Q_8$ x 3, $D_4$ x 3, $C_8$ x 3

Order 4: $C_4$ x 4, $C_2^2$ x 2

Order 2: $C_2$ x 3

Order 1: $C_1$

Normal subgroups (quotient in parentheses)

Order 128: $C_2.D_4^2$ ($C_1$)

Order 64: $D_4.D_4$ ($C_2$) x 4, $C_8.D_4$ ($C_2$) x 4, $D_4.D_4$ ($C_2$) x 4, $D_8:C_4$ ($C_2$) x 2, $C_4:Q_{16}$ ($C_2$)

Order 32: $Q_{16}:C_2$ ($C_2^2$) x 8, $C_4.D_4$ ($C_2^2$) x 4, $C_4.C_2^3$ ($C_2^2$) x 4, $C_2\times Q_{16}$ ($C_2^2$) x 4, $\OD_{16}:C_2$ ($C_2^2$) x 4, $C_4\wr C_2$ ($C_2^2$) x 4, $D_8:C_2$ ($C_2^2$) x 2, $C_4:Q_8$ ($C_2^2$) x 2, $C_8.C_4$ ($C_2^2$) x 2, $C_4\times C_8$ ($C_2^2$)

Order 16: $\SD_{16}$ ($D_4$) x 4, $\OD_{16}$ ($C_2^3$) x 4, $D_4:C_2$ ($C_2^3$) x 4, $C_2\times Q_8$ ($C_2^3$) x 4, $Q_{16}$ ($D_4$) x 2, $D_8$ ($D_4$) x 2, $C_2\times C_8$ ($C_2^3$) x 2, $C_4^2$ ($C_2^3$)

Order 8: $Q_8$ ($C_2\times D_4$) x 4, $D_4$ ($C_2\times D_4$) x 4, $C_8$ ($C_2\times D_4$) x 4, $C_2\times C_4$ ($C_2^4$)

Order 4: $C_4$ ($C_2^2\times D_4$) x 2, $C_2^2$ ($D_4:C_2^2$)

Order 2: $C_2$ ($D_4^2$)

Order 1: $C_1$ ($C_2.D_4^2$)

Normal subgroups up to automorphism (quotient in parentheses)

Order 128: $C_2.D_4^2$ ($C_1$)

Order 64: $D_4.D_4$ ($C_2$), $C_4:Q_{16}$ ($C_2$), $C_8.D_4$ ($C_2$), $D_4.D_4$ ($C_2$), $D_8:C_4$ ($C_2$)

Order 32: $C_4.D_4$ ($C_2^2$), $C_4.C_2^3$ ($C_2^2$), $Q_{16}:C_2$ ($C_2^2$), $D_8:C_2$ ($C_2^2$), $C_2\times Q_{16}$ ($C_2^2$), $\OD_{16}:C_2$ ($C_2^2$), $C_4:Q_8$ ($C_2^2$), $C_4\times C_8$ ($C_2^2$), $C_8.C_4$ ($C_2^2$), $C_4\wr C_2$ ($C_2^2$)

Order 16: $Q_{16}$ ($D_4$), $\SD_{16}$ ($D_4$), $D_8$ ($D_4$), $\OD_{16}$ ($C_2^3$), $C_2\times C_8$ ($C_2^3$), $C_4^2$ ($C_2^3$), $D_4:C_2$ ($C_2^3$), $C_2\times Q_8$ ($C_2^3$)

Order 8: $C_8$ ($C_2\times D_4$) x 2, $Q_8$ ($C_2\times D_4$), $D_4$ ($C_2\times D_4$), $C_2\times C_4$ ($C_2^4$)

Order 4: $C_2^2$ ($D_4:C_2^2$), $C_4$ ($C_2^2\times D_4$)

Order 2: $C_2$ ($D_4^2$)

Order 1: $C_1$ ($C_2.D_4^2$)

Series

Derived series

$C_2.D_4^2$

$\rhd$

$C_2\times C_4$

$\rhd$

$C_1$

Chief series

$C_2.D_4^2$

$\rhd$

$D_8:C_4$

$\rhd$

$D_8:C_2$

$\rhd$

$C_2\times C_8$

$\rhd$

$C_2\times C_4$

$\rhd$

$C_4$

$\rhd$

$C_2$

$\rhd$

$C_1$

Lower central series

$C_2.D_4^2$

$\rhd$

$C_2\times C_4$

$\rhd$

$C_2$

$\rhd$

$C_1$

Upper central series

$C_1$

$\lhd$

$C_2$

$\lhd$

$C_2\times C_4$

$\lhd$

$C_2.D_4^2$

Supergroups

This group is a maximal subgroup of 21 larger groups in the database.

This group is a maximal quotient of 102 larger groups in the database.

Character theory

Complex character table

See the $29 \times 29$ character table. Alternatively, you may search for characters of this group with desired properties.

Rational character table

See the $27 \times 27$ rational character table.