2847. Smallest Number With Given Digit Product

Find the prime factors of n.

If there is a prime factor p such that p >= 11, the answer is -1. Since there are no digits whose products equal p.

Factors 5 and 7 should be included in the answer since their product with any number bigger than 1 is a 2-digit number.

For factors 2 and 3, we group every three 2 into an 8 and every two 3 into a 9.

For any leftover 2 or 3, check all the possible combinations.