Numbers / 765

The Number 765

765 is composite: factorization 3^2 × 5 × 17. That gives 765 exactly 12 divisors: 1, 3, 5, 9, 15, 17, 45, 51, 85, 153, 255, 765. 765's proper divisors total just 639, 126 short of 765, the deficient case most of 765's neighbors share too. 765 has a digit sum of 18; for 765, the digital root works out to 9. 765: 3, 5, 9 all divide 765 evenly, out of 2-12. 765 is 1011111101 in binary and 2FD in hex; as a Roman numeral it's DCCLXV.