Group has Subgroups of All Prime Power Factors

Theorem
Let $p$ be a prime.

Let $G$ be a finite group of order $n$.

If $p^k \mathop \backslash n$ then $G$ has at least one subgroup order $p^k$.

Proof
From Composition Series of Group of Prime Power Order, a $p$-group has subgroups corresponding to every divisor of its order.

Thus, taken with the First Sylow Theorem, a finite group has a subgroup corresponding to every prime power divisor of its order.