Question 14
For a positive integer $n$ we write out all its divisors $1 = d_1 \lt d_2 \lt \cdots \lt d_k = n$. A divisor $d_i$, $2 \le i \le k-1$, is called a good divisor if $d_{i-1}d_{i+1}$ is not divisible by $d_i$. Find all $n$ for which the number of their good divisors is smaller than the number of their different prime divisors.
(Mykhailo Shtandenko)
(Mykhailo Shtandenko)