Numbers / 690

The Number 690

690 is composite: factorization 2 × 3 × 5 × 23. That gives 690 exactly 16 divisors: 1, 2, 3, 5, 6, 10, 15, 23, 30, 46, 69, 115, 138, 230, 345, 690. 690's proper divisors total 1038, 348 more than 690 itself, so 690 is abundant. 690 has a digit sum of 15; for 690, the digital root works out to 6. 690: 2, 3, 5, 6, 10 all divide 690 evenly, out of 2-12. 690 is 1010110010 in binary and 2B2 in hex; as a Roman numeral it's DCXC.