Numbers / 648

The Number 648

648 is composite: factorization 2^3 × 3^4. That gives 648 exactly 20 divisors: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 27, 36, 54, 72, 81, 108, 162, 216, 324, 648. 648's proper divisors total 1167, 519 more than 648 itself, so 648 is abundant. 648 has a digit sum of 18; for 648, the digital root works out to 9. 648: 2, 3, 4, 6, 8, 9, 12 all divide 648 evenly, out of 2-12. 648 is 1010001000 in binary and 288 in hex; as a Roman numeral it's DCXLVIII.