Numbers / 840
The Number 840
840 is composite: factorization 2^3 × 3 × 5 × 7. That gives 840 exactly 32 divisors: 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28, 30, 35, 40, 42, 56, 60, 70, 84, 105, 120, 140, 168, 210, 280, 420, 840. 840's proper divisors total 2040, 1200 more than 840 itself, so 840 is abundant. 840 has a digit sum of 12; for 840, the digital root works out to 3. 840: 2, 3, 4, 5, 6, 7, 8, 10, 12 all divide 840 evenly, out of 2-12. 840 is 1101001000 in binary and 348 in hex; as a Roman numeral it's DCCCXL.