Numbers / 281

The Number 281

281 is prime: only 1 and 281 divide it evenly; the next prime after 281 is 283. 281's proper divisors total just 1, 280 short of 281, the deficient case most of 281's neighbors share too. 281 has a digit sum of 11; for 281, the digital root works out to 2. 281 shares no factor with 2-12; 281's own divisors start beyond that range. 281 is 100011001 in binary and 119 in hex; as a Roman numeral it's CCLXXXI.