Finite Group DatabasebetaFinite Group DatabasebetaOrder 84.
20 conjugacy classes of subgroups.
| # | subgroup | G/H | class size | multiplicity | normal? | properties |
|---|---|---|---|---|---|---|
| 1 | D21 | C2 | 1 | 1 | yes | maximal, characteristic, complemented |
| 2 | C3×D7 | C2 | 1 | 1 | yes | maximal, characteristic, complemented |
| 3 | D3×C7 | C2 | 1 | 1 | yes | maximal, characteristic, complemented |
| 4 | C2×D7 | — | 3 | 1 | no | maximal, Hall |
| 5 | C3×C7 | C22 | 1 | 1 | yes | characteristic, complemented, Hall |
| 6 | C2×C7 | — | 3 | 1 | no | — |
| 7 | D7 | — | 3 | 1 | no | — |
| 8 | D7 | D3 | 1 | 1 | yes | characteristic, direct product factor |
| 9 | C2×D3 | — | 7 | 1 | no | maximal, Hall |
| 10 | C7 | C2×D3 | 1 | 1 | yes | characteristic, complemented, Sylow |
| 11 | C2×C3 | — | 7 | 1 | no | — |
| 12 | D3 | — | 7 | 1 | no | — |
| 13 | D3 | D7 | 1 | 1 | yes | characteristic, direct product factor |
| 14 | C22 | — | 21 | 1 | no | Sylow |
| 15 | C3 | C2×D7 | 1 | 1 | yes | characteristic, complemented, Sylow |
| 16 | C2 | — | 3 | 1 | no | — |
| 17 | C2 | — | 7 | 1 | no | — |
| 18 | C2 | — | 21 | 1 | no | — |
| subgroup | G/H | |
|---|---|---|
| center, Frattini, hypercenter | C1 | G |
| commutator, Fitting, socle, cosocle, hypocenter | C3×C7 | C22 |
| LCS | G ▷ C3×C7 | |
| UCS | C1 | |
Splittings G = N ⋊ H with N normal; H ≅ G/N.
| N | H ≅ G/N | type |
|---|---|---|
| 1. D21 | C2 | semidirect |
| 2. C3×D7 | C2 | semidirect |
| 3. D3×C7 | C2 | semidirect |
| 5. C3×C7 | C22 | semidirect |
| 8. D7 | D3 | direct (N × H) |
| 10. C7 | C2×D3 | semidirect |
| 13. D3 | D7 | direct (N × H) |
| 15. C3 | C2×D7 | semidirect |
By isomorphism type — maximal subgroups of the same type appear once, whether or not they are normal.
| subgroup | index |
|---|---|
| D21 | 2 |
| C3×D7 | 2 |
| D3×C7 | 2 |
| C2×D7 | 3 |
| C2×D3 | 7 |