Numbers / 57

The Number 57

57 is composite: factorization 3 × 19. That gives 57 exactly 4 divisors: 1, 3, 19, 57. 57's proper divisors total just 23, 34 short of 57, the deficient case most of 57's neighbors share too. 57 has a digit sum of 12; for 57, the digital root works out to 3. 57: 3 all divide 57 evenly, out of 2-12. 57 is 111001 in binary and 39 in hex; as a Roman numeral it's LVII.