CAT (QA) PYQs

The sum of the first two natural numbers, each having $15$ factors (including $1$ and the number itself), is

How many pairs $(a, b)$ of positive integers are there such that $a \le b$ and $ab =$ $4^{2017}$?

If $m$ and $n$ are natural numbers such that $n > 1$, and $m^{n}=2^{25} \times 3^{40}$, then $m-n$ equals