Numbers / 247

The Number 247

247 is composite: factorization 13 × 19. That gives 247 exactly 4 divisors: 1, 13, 19, 247. 247's proper divisors total just 33, 214 short of 247, the deficient case most of 247's neighbors share too. 247 has a digit sum of 13; for 247, the digital root works out to 4. 247 shares no factor with 2-12; 247's own divisors start beyond that range. 247 is 11110111 in binary and F7 in hex; as a Roman numeral it's CCXLVII.