Question 23
For positive integers $m, n$, let $\operatorname{gcd}(m, n)$ denote the largest positive integer that is a factor of both $m$ and $n$. Compute
$$
\sum_{n=1}^{91} \operatorname{gcd}(n, 91) .
$$
$$
\sum_{n=1}^{91} \operatorname{gcd}(n, 91) .
$$