  In 2000, L. H\'{e}thelyi and B. K\"{u}lshammer proved that if $p$ is a prime
number dividing the order of a finite solvable group $G$, then $G$ has at least
$2\sqrt{p-1}$ conjugacy classes. In this paper we show that if $p$ is large,
the result remains true for arbitrary finite groups.
