Factors / Factors of 91

Factors of 91

1, 7, 13, 91

91 breaks into 2 pairs, tested up to √91 ≈ 9.5; each pair multiplies back to 91 exactly. 91's full pair list is (1, 91), (7, 13), for 4 divisors in total. 91's divisors other than 91 itself sum to just 21, 70 below 91: the common deficient case. 91 is odd, digit sum 10 for 91; small divisors of 91 include 7. 91 has 4 divisors; 90 has 12 and 92 has 6, so 90 wins here. 91 divided by its largest divisor, 13, gives 7.