  In this paper we completely classify nontrivial semisimple Hopf algebras of
dimension 16. We also compute all the possible structures of the Grothendieck
ring of semisimple non-commutative Hopf algebras of dimension 16. Moreover, we
prove that non-commutative semisimple Hopf algebras of dimension p^n, p is
prime, cannot have a cyclic group of grouplikes.
