Numbers / 613

The Number 613

613 is prime: only 1 and 613 divide it evenly; the next prime after 613 is 617. 613's proper divisors total just 1, 612 short of 613, the deficient case most of 613's neighbors share too. 613 has a digit sum of 10; for 613, the digital root works out to 1. 613 shares no factor with 2-12; 613's own divisors start beyond that range. 613 is 1001100101 in binary and 265 in hex; as a Roman numeral it's DCXIII.