Summary: We study the group structure in terms of the number of Sylow $p$-subgroups, which is denoted by $n_p(G)$. The first part is on the group structure of finite group $G$ such that $n_p(G)=n_p(G/N)$, where $N$ is a normal subgroup of $G$. The second part is on the average Sylow number ${\rm asn}(G)$ and we prove that if $G$ is a finite nonsolvable group with ${\rm asn}(G)<39/4$ and ${\rm asn}(G)\neq 29/4$, then $G/F(G)\cong A_5$, where $F(G)$ is the Fitting subgroup of $G$. In the third part, we study the nonsolvable group with small sum of Sylow numbers.
References:
[1] Anabanti, C. S., Moretó, A., Zarrin, M.: Influence of the number of Sylow subgroups on solvability of finite groups. C. R. Math., Acad. Sci. Paris 358 (2020), 1227-1230. DOI 10.5802/crmath.146 | MR 4206543 | Zbl 1472.20027
[5] Conway, J. H., Curtis, R. T., Norton, S. P., Parker, R. A., Wilson, R. A.: Atlas of Finite Groups: Maximal Subgroups and Ordinary Characters for Simple Groups. Oxford University Press, Oxford (1985). MR 0827219 | Zbl 0568.20001