# Groups of order 512

## Contents

See pages on algebraic structures of order 512| See pages on groups of a particular order

## Statistics at a glance

Note that since $512 = 2^9$ is a prime power, and prime power order implies nilpotent, all groups of order 512 are nilpotent groups.

Quantity Value Greatest integer function of logarithm of value to base 2 Explanation for value
Number of groups up to isomorphism 10494213 23
Number of abelian groups up to isomorphism 30 4 Equals the number of unordered integer partitions of $9$. See classification of finite abelian groups.
Number of maximal class groups, i.e., groups of nilpotency class exactly $9 - 1 = 8$ 3 1 The dihedral group, semidihedral group, and generalized quaternion group. See classification of finite 2-groups of maximal class.

## GAP implementation

The order 512 is part of GAP's SmallGroup library. Hence, any group of order 512 can be constructed using the SmallGroup function by specifying its group ID. Unfortunately, IdGroup is not available for this order, i.e., given a group of this order, it is not possible to directly query GAP to find its GAP ID.

Further, the collection of all groups of order 512 can be accessed as a list using GAP's AllSmallGroups function. However, the list size may be too large relative to the memory allocation given in typical GAP installations. To overcome this problem, use the IdsOfAllSmallGroups function which stores and manipulates only the group IDs, not the groups themselves.

Here is GAP's summary information about how it stores groups of this order, accessed using GAP's SmallGroupsInformation function:

```gap> SmallGroupsInformation(512);

There are 10494213 groups of order 512.
1 is cyclic.
2 - 10 have rank 2 and p-class 3.
11 - 386 have rank 2 and p-class 4.
387 - 1698 have rank 2 and p-class 5.
1699 - 2008 have rank 2 and p-class 6.
2009 - 2039 have rank 2 and p-class 7.
2040 - 2044 have rank 2 and p-class 8.
2045 has rank 3 and p-class 2.
2046 - 29398 have rank 3 and p-class 3.
29399 - 30617 have rank 3 and p-class 4.
30618 - 31239 have rank 3 and p-class 3.
31240 - 56685 have rank 3 and p-class 4.
56686 - 60615 have rank 3 and p-class 5.
60616 - 60894 have rank 3 and p-class 6.
60895 - 60903 have rank 3 and p-class 7.
60904 - 67612 have rank 4 and p-class 2.
67613 - 387088 have rank 4 and p-class 3.
387089 - 419734 have rank 4 and p-class 4.
419735 - 420500 have rank 4 and p-class 5.
420501 - 420514 have rank 4 and p-class 6.
420515 - 6249623 have rank 5 and p-class 2.
6249624 - 7529606 have rank 5 and p-class 3.
7529607 - 7532374 have rank 5 and p-class 4.
7532375 - 7532392 have rank 5 and p-class 5.
7532393 - 10481221 have rank 6 and p-class 2.
10481222 - 10493038 have rank 6 and p-class 3.
10493039 - 10493061 have rank 6 and p-class 4.
10493062 - 10494173 have rank 7 and p-class 2.
10494174 - 10494200 have rank 7 and p-class 3.
10494201 - 10494212 have rank 8 and p-class 2.
10494213 is elementary abelian.

This size belongs to layer 7 of the SmallGroups library.
IdSmallGroup is not available for this size.```