10.4. Find the smallest natural number $n$ for which a) $n!$ is divisible by 2016; b) $n!$ is divisible by $2016^{10}$. (Recall that $\left.n!=1 \cdot 2 \cdot 3 \cdot \ldots \cdot n.\right)$
Answer: a) $n=8 ;$ b) $n=63$. Solution. See problem 9.4 .