Numbers / 671

The Number 671

671 is composite: factorization 11 × 61. That gives 671 exactly 4 divisors: 1, 11, 61, 671. 671's proper divisors total just 73, 598 short of 671, the deficient case most of 671's neighbors share too. 671 has a digit sum of 14; for 671, the digital root works out to 5. 671: 11 all divide 671 evenly, out of 2-12. 671 is 1010011111 in binary and 29F in hex; as a Roman numeral it's DCLXXI.