186 Divide by two.
93,2 Divide by three.
31,3,2 Stop. All the factors are prime.
2 x 3 x 31 = 186
13 is already prime. It doesn't need a tree.
126 ^ 9 14 ^ ^ 3 3 7 2
56 28,2 14,2,2 7,2,2,2
484 242,2 121,2,2 11,11,2,2
675 225,3 75,3,3 25,3,3,3 5,5,3,3,3
126 63,2 21,3,2 7,3,3,2
126 63,2 21,3,2 7,3,3,2
126 63,2 21,3,2 7,3,3,2
126 63,2 21,3,2 7,3,3,2
126 63,2 21,3,2 7,3,3,2
2,3,3,7
Factor tree:126|63 and 2|21 and 32 x 3 x 21 = 126
77 7,11
15 3,5
1,270,2,135
23 is a prime number. No prime factorization. No tree.
13 is already prime. It doesn't need a tree.