Factors / Factors of 400

Factors of 400

1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400

400 is a perfect square (20² = 400); that gives 400 an odd 15-divisor count, since only 20 pairs with itself. 400's full pair list is (1, 400), (2, 200), (4, 100), (5, 80), (8, 50), (10, 40), (16, 25), (20, 20), for 15 divisors in total. 400's divisors other than 400 itself sum to 561, 161 above 400: abundant. 400 is even, digit sum 4 for 400; small divisors of 400 include 2, 4, 5, 8, 10. 400 has 15 divisors; 399 has 8 and 401 has 2, so 400 wins here. 400 divided by its largest divisor, 200, gives 2.