Numbers / 684

The Number 684

684 is composite: factorization 2^2 × 3^2 × 19. That gives 684 exactly 18 divisors: 1, 2, 3, 4, 6, 9, 12, 18, 19, 36, 38, 57, 76, 114, 171, 228, 342, 684. 684's proper divisors total 1136, 452 more than 684 itself, so 684 is abundant. 684 has a digit sum of 18; for 684, the digital root works out to 9. 684: 2, 3, 4, 6, 9, 12 all divide 684 evenly, out of 2-12. 684 is 1010101100 in binary and 2AC in hex; as a Roman numeral it's DCLXXXIV.