2023/006) Find 2 digit numbers that have exactly 5 factors

 If the umber is of the form $\prod_{n=1}^{k}p_n^{q_n}$ then the number of factors = $\prod_{n=1}^{k}(q_n+1)$

Because 5 is prime the number must be of the form $p^4$ where p is prime

We have the number of digits =2 and we should find p such that $ 9 \lt p^4 \lt 100$

The only number that satsfies the condition is n = 2 and n is a prime and $2^4= 16$

So 16 is the only 2 digit number having 5 factors