Certain properties of the enhanced power graph associated with a finite group

The enhanced power graph of a finite group $G$, denoted by ${\mathcal{P}}_E(G)$, is the simple undirected graph whose vertex set is $G$ and two distinct vertices $x,y$ are adjacent if $x,y\in ⟨z⟩$ for some $z\in G$. In this article, we determine all finite groups such that the minimum degree and the vertex connectivity of ${\mathcal{P}}_E(G)$ are equal. Also, we classify all groups whose (proper) enhanced power graphs are strongly regular. Further, the vertex connectivity of the enhanced power graphs associated to some nilpotent groups is obtained. Finally, we obtain a lower bound and an upper bound for the Wiener index of ${\mathcal{P}}_E(G)$, where $G$ is a nilpotent group. The finite nilpotent groups attaining these bounds are also characterized.