factors for 72 and 48
72- 2, 3, 4, 6, 8, 9, 12, 18, 24, 3648- 2, 3, 4, 6, 8, 12, 16, 24
1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 721, 2, 3, 4, 6, 8, 12, 16, 24, 48pretty easy ;)