Factors / Factors of 309

Factors of 309

1, 3, 103, 309

309 breaks into 2 pairs, tested up to √309 ≈ 17.6; each pair multiplies back to 309 exactly. 309's full pair list is (1, 309), (3, 103), for 4 divisors in total. 309's divisors other than 309 itself sum to just 107, 202 below 309: the common deficient case. 309 is odd, digit sum 12 for 309; small divisors of 309 include 3. 309 has 4 divisors; 308 has 12 and 310 has 8, so 308 wins here. 309 divided by its largest divisor, 103, gives 3.