Factors / Factors of 261

Factors of 261

1, 3, 9, 29, 87, 261

261 breaks into 3 pairs, tested up to √261 ≈ 16.2; each pair multiplies back to 261 exactly. 261's full pair list is (1, 261), (3, 87), (9, 29), for 6 divisors in total. 261's divisors other than 261 itself sum to just 129, 132 below 261: the common deficient case. 261 is odd, digit sum 9 for 261; small divisors of 261 include 3, 9. 261 has 6 divisors; 260 has 12 and 262 has 4, so 260 wins here. 261 divided by its largest divisor, 87, gives 3.