Numbers / 997

The Number 997

997 is prime: only 1 and 997 divide it evenly; the next prime after 997 is 1009. 997's proper divisors total just 1, 996 short of 997, the deficient case most of 997's neighbors share too. 997 has a digit sum of 25; for 997, the digital root works out to 7. 997 shares no factor with 2-12; 997's own divisors start beyond that range. 997 is 1111100101 in binary and 3E5 in hex; as a Roman numeral it's CMXCVII.