5023 because it's a prime number
1997 is already prime; no tree.
51 3,17
350=2x5x5x7
33 11,3
a prime factorization tree
5023 is the 674th prime number. Its only prime factor is itself.
50 25,2 5,5,2
97 is already prime; no tree.
131 is already prime. No tree.
141 = 3 x 47
572=2x286=2x2x143=2x2x11x13