Numbers / 321

The Number 321

321 is composite: factorization 3 × 107. That gives 321 exactly 4 divisors: 1, 3, 107, 321. 321's proper divisors total just 111, 210 short of 321, the deficient case most of 321's neighbors share too. 321 has a digit sum of 6; for 321, the digital root works out to 6. 321: 3 all divide 321 evenly, out of 2-12. 321 is 101000001 in binary and 141 in hex; as a Roman numeral it's CCCXXI.