10. There are $n$ locks numbered $1,2, \cdots, n$, all of which are initially locked. Now, a series of operations $T_{1}, T_{2}, \cdots, T_{n}$ are performed sequentially, where operation $T_{k}(1 \leqslant k \leqslant n)$ only changes the state of the locks whose numbers are multiples of $k$. After $n$ operations, which locks are open?
10. $1 \leqslant m \leqslant n$, let $m=\mathrm{P}_{1}^{a_{1}} \mathrm{P}_{2_{2}^{2}}^{a_{1}} \cdots \mathrm{P}_{5}^{a_{5}},$ the number of positive divisors of $m$ is $\prod_{i=1}^{5}\left(\alpha_{i}+1\right)$, the $m$-th lock is open if and only if the number of positive divisors of $m$ is odd, i.e., when $m$ is a perfect square, the lock is open.