Numbers / 815

The Number 815

815 is composite: factorization 5 × 163. That gives 815 exactly 4 divisors: 1, 5, 163, 815. 815's proper divisors total just 169, 646 short of 815, the deficient case most of 815's neighbors share too. 815 has a digit sum of 14; for 815, the digital root works out to 5. 815: 5 all divide 815 evenly, out of 2-12. 815 is 1100101111 in binary and 32F in hex; as a Roman numeral it's DCCCXV.