Numbers / 197

The Number 197

197 is prime: only 1 and 197 divide it evenly; the next prime after 197 is 199. 197's proper divisors total just 1, 196 short of 197, the deficient case most of 197's neighbors share too. 197 has a digit sum of 17; for 197, the digital root works out to 8. 197 shares no factor with 2-12; 197's own divisors start beyond that range. 197 is 11000101 in binary and C5 in hex; as a Roman numeral it's CXCVII.