Numbers / 656

The Number 656

656 is composite: factorization 2^4 × 41. That gives 656 exactly 10 divisors: 1, 2, 4, 8, 16, 41, 82, 164, 328, 656. 656's proper divisors total just 646, 10 short of 656, the deficient case most of 656's neighbors share too. 656 is also a palindrome, since 656 reads identically forwards and backwards. 656 has a digit sum of 17; for 656, the digital root works out to 8. 656: 2, 4, 8 all divide 656 evenly, out of 2-12. 656 is 1010010000 in binary and 290 in hex; as a Roman numeral it's DCLVI.