Numbers / 619

The Number 619

619 is prime: only 1 and 619 divide it evenly; the next prime after 619 is 631. 619's proper divisors total just 1, 618 short of 619, the deficient case most of 619's neighbors share too. 619 has a digit sum of 16; for 619, the digital root works out to 7. 619 shares no factor with 2-12; 619's own divisors start beyond that range. 619 is 1001101011 in binary and 26B in hex; as a Roman numeral it's DCXIX.