Factors / Factors of 20

Factors of 20

1, 2, 4, 5, 10, 20

20 breaks into 3 pairs, tested up to √20 ≈ 4.5; each pair multiplies back to 20 exactly. 20's full pair list is (1, 20), (2, 10), (4, 5), for 6 divisors in total. 20's divisors other than 20 itself sum to 22, 2 above 20: abundant. 20 is even, digit sum 2 for 20; small divisors of 20 include 2, 4, 5, 10. 20 has 6 divisors; 19 has 2 and 21 has 4, so 20 wins here. 20 divided by its largest divisor, 10, gives 2.