Numbers / 813

The Number 813

813 is composite: factorization 3 × 271. That gives 813 exactly 4 divisors: 1, 3, 271, 813. 813's proper divisors total just 275, 538 short of 813, the deficient case most of 813's neighbors share too. 813 has a digit sum of 12; for 813, the digital root works out to 3. 813: 3 all divide 813 evenly, out of 2-12. 813 is 1100101101 in binary and 32D in hex; as a Roman numeral it's DCCCXIII.