Numbers / 720
The Number 720
720 is composite: factorization 2^4 × 3^2 × 5. That gives 720 exactly 30 divisors: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360, 720. 720's proper divisors total 1698, 978 more than 720 itself, so 720 is abundant. 720 has a digit sum of 9; for 720, the digital root works out to 9. 720: 2, 3, 4, 5, 6, 8, 9, 10, 12 all divide 720 evenly, out of 2-12. 720 is 1011010000 in binary and 2D0 in hex; as a Roman numeral it's DCCXX.