Numbers / 780

The Number 780

780 is composite: factorization 2^2 × 3 × 5 × 13. That gives 780 exactly 24 divisors: 1, 2, 3, 4, 5, 6, 10, 12, 13, 15, 20, 26, 30, 39, 52, 60, 65, 78, 130, 156, 195, 260, 390, 780. 780's proper divisors total 1572, 792 more than 780 itself, so 780 is abundant. 780 is also the 39th triangular number, the sum of 1 through 39. 780 has a digit sum of 15; for 780, the digital root works out to 6. 780: 2, 3, 4, 5, 6, 10, 12 all divide 780 evenly, out of 2-12. 780 is 1100001100 in binary and 30C in hex; as a Roman numeral it's DCCLXXX.