Numbers / 591

The Number 591

591 is composite: factorization 3 × 197. That gives 591 exactly 4 divisors: 1, 3, 197, 591. 591's proper divisors total just 201, 390 short of 591, the deficient case most of 591's neighbors share too. 591 has a digit sum of 15; for 591, the digital root works out to 6. 591: 3 all divide 591 evenly, out of 2-12. 591 is 1001001111 in binary and 24F in hex; as a Roman numeral it's DXCI.