Numbers / 173

The Number 173

173 is prime: only 1 and 173 divide it evenly; the next prime after 173 is 179. 173's proper divisors total just 1, 172 short of 173, the deficient case most of 173's neighbors share too. 173 has a digit sum of 11; for 173, the digital root works out to 2. 173 shares no factor with 2-12; 173's own divisors start beyond that range. 173 is 10101101 in binary and AD in hex; as a Roman numeral it's CLXXIII.