Numbers / 491

The Number 491

491 is prime: only 1 and 491 divide it evenly; the next prime after 491 is 499. 491's proper divisors total just 1, 490 short of 491, the deficient case most of 491's neighbors share too. 491 has a digit sum of 14; for 491, the digital root works out to 5. 491 shares no factor with 2-12; 491's own divisors start beyond that range. 491 is 111101011 in binary and 1EB in hex; as a Roman numeral it's CDXCI.