Some results on Sylow numbers of finite groups
We study the group structure in terms of the number of Sylow -subgroups, which is denoted by . The first part is on the group structure of finite group such that , where is a normal subgroup of . The second part is on the average Sylow number and we prove that if is a finite nonsolvable group with and , then , where is the Fitting subgroup of . In the third part, we study the nonsolvable group with small sum of Sylow numbers.