Numbers / 72

The Number 72

72 is composite: factorization 2^3 × 3^2. That gives 72 exactly 12 divisors: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72. 72's proper divisors total 123, 51 more than 72 itself, so 72 is abundant. 72 has a digit sum of 9; for 72, the digital root works out to 9. 72: 2, 3, 4, 6, 8, 9, 12 all divide 72 evenly, out of 2-12. 72 is 1001000 in binary and 48 in hex; as a Roman numeral it's LXXII.