Numbers / 653

The Number 653

653 is prime: only 1 and 653 divide it evenly; the next prime after 653 is 659. 653's proper divisors total just 1, 652 short of 653, the deficient case most of 653's neighbors share too. 653 has a digit sum of 14; for 653, the digital root works out to 5. 653 shares no factor with 2-12; 653's own divisors start beyond that range. 653 is 1010001101 in binary and 28D in hex; as a Roman numeral it's DCLIII.