Numbers / 71

The Number 71

71 is prime: only 1 and 71 divide it evenly; the next prime after 71 is 73. 71's proper divisors total just 1, 70 short of 71, the deficient case most of 71's neighbors share too. 71 has a digit sum of 8; for 71, the digital root works out to 8. 71 shares no factor with 2-12; 71's own divisors start beyond that range. 71 is 1000111 in binary and 47 in hex; as a Roman numeral it's LXXI.