For distinct primes $p$ and $q$, how many nonabelian groups up to isomorphism are of the order $p^4*q^4$?
We can say that there are nontrivial subgroups with cardinality $p,p^2,p^3,p^4,p*q,..,q^4$. Since we are dealing with nonabelian groups, we can't say a group with cardinality $p^4*q^4$ is isomorpic to $$Z_(p^4*q^4)$$. Should I consider $$U_(p^4*q^4)$$ ?