193 is already prime; no factorization.
193 is prime. No tree.
1997 is already prime; no tree.
579 = 3 x 193
2 x 193 = 386
51 3,17
350=2x5x5x7
33 11,3
a prime factorization tree
50 25,2 5,5,2
97 is already prime; no tree.
131 is already prime. No tree.