Numbers / 431

The Number 431

431 is prime: only 1 and 431 divide it evenly; the next prime after 431 is 433. 431's proper divisors total just 1, 430 short of 431, the deficient case most of 431's neighbors share too. 431 has a digit sum of 8; for 431, the digital root works out to 8. 431 shares no factor with 2-12; 431's own divisors start beyond that range. 431 is 110101111 in binary and 1AF in hex; as a Roman numeral it's CDXXXI.