Numbers / 517

The Number 517

517 is composite: factorization 11 × 47. That gives 517 exactly 4 divisors: 1, 11, 47, 517. 517's proper divisors total just 59, 458 short of 517, the deficient case most of 517's neighbors share too. 517 has a digit sum of 13; for 517, the digital root works out to 4. 517: 11 all divide 517 evenly, out of 2-12. 517 is 1000000101 in binary and 205 in hex; as a Roman numeral it's DXVII.