Numbers / 199

The Number 199

199 is prime: only 1 and 199 divide it evenly; the next prime after 199 is 211. 199's proper divisors total just 1, 198 short of 199, the deficient case most of 199's neighbors share too. 199 has a digit sum of 19; for 199, the digital root works out to 1. 199 shares no factor with 2-12; 199's own divisors start beyond that range. 199 is 11000111 in binary and C7 in hex; as a Roman numeral it's CXCIX.