Numbers / 871

The Number 871

871 is composite: factorization 13 × 67. That gives 871 exactly 4 divisors: 1, 13, 67, 871. 871's proper divisors total just 81, 790 short of 871, the deficient case most of 871's neighbors share too. 871 has a digit sum of 16; for 871, the digital root works out to 7. 871 shares no factor with 2-12; 871's own divisors start beyond that range. 871 is 1101100111 in binary and 367 in hex; as a Roman numeral it's DCCCLXXI.