Subgroup ($H$) information
| Description: | $C_{15}$ | 
| Order: | \(15\)\(\medspace = 3 \cdot 5 \) | 
| Index: | \(56\)\(\medspace = 2^{3} \cdot 7 \) | 
| Exponent: | \(15\)\(\medspace = 3 \cdot 5 \) | 
| Generators: | $b^{280}, b^{252}$ | 
| Nilpotency class: | $1$ | 
| Derived length: | $1$ | 
The subgroup is characteristic (hence normal), a semidirect factor, cyclic (hence abelian, nilpotent, solvable, supersolvable, monomial, elementary ($p = 3,5$), hyperelementary, metacyclic, metabelian, a Z-group, and an A-group), and a Hall subgroup.
Ambient group ($G$) information
| Description: | $C_5\times D_{84}$ | 
| Order: | \(840\)\(\medspace = 2^{3} \cdot 3 \cdot 5 \cdot 7 \) | 
| Exponent: | \(420\)\(\medspace = 2^{2} \cdot 3 \cdot 5 \cdot 7 \) | 
| Derived length: | $2$ | 
The ambient group is nonabelian, metacyclic (hence solvable, supersolvable, monomial, and metabelian), and hyperelementary for $p = 2$.
Quotient group ($Q$) structure
| Description: | $D_{28}$ | 
| Order: | \(56\)\(\medspace = 2^{3} \cdot 7 \) | 
| Exponent: | \(28\)\(\medspace = 2^{2} \cdot 7 \) | 
| Automorphism Group: | $D_4\times F_7$, of order \(336\)\(\medspace = 2^{4} \cdot 3 \cdot 7 \) | 
| Outer Automorphisms: | $C_2\times C_6$, of order \(12\)\(\medspace = 2^{2} \cdot 3 \) | 
| Nilpotency class: | $-1$ | 
| Derived length: | $2$ | 
The quotient is nonabelian, metacyclic (hence solvable, supersolvable, monomial, and metabelian), and hyperelementary for $p = 2$.
Automorphism information
Since the subgroup $H$ is characteristic, the automorphism group $\operatorname{Aut}(G)$ of the ambient group acts on $H$, yielding a homomorphism $\operatorname{res} : \operatorname{Aut}(G) \to \operatorname{Aut}(H)$. The image of $\operatorname{res}$ on the inner automorphism group $\operatorname{Inn}(G)$ is the Weyl group $W = G / Z_G(H)$.
| $\operatorname{Aut}(G)$ | $C_{42}.(C_2^4\times C_{12})$ | 
| $\operatorname{Aut}(H)$ | $C_2\times C_4$, of order \(8\)\(\medspace = 2^{3} \) | 
| $\operatorname{res}(\operatorname{Aut}(G))$ | $C_2\times C_4$, of order \(8\)\(\medspace = 2^{3} \) | 
| $\card{\operatorname{ker}(\operatorname{res})}$ | \(1008\)\(\medspace = 2^{4} \cdot 3^{2} \cdot 7 \) | 
| $W$ | $C_2$, of order \(2\) | 
Related subgroups
| Centralizer: | $C_{420}$ | |||
| Normalizer: | $C_5\times D_{84}$ | |||
| Complements: | $D_{28}$ | |||
| Minimal over-subgroups: | $C_{105}$ | $C_{30}$ | $C_5\times S_3$ | $C_5\times S_3$ | 
| Maximal under-subgroups: | $C_5$ | $C_3$ | 
Other information
| Möbius function | $0$ | 
| Projective image | $D_{84}$ | 
