Numbers / 291

The Number 291

291 is composite: factorization 3 × 97. That gives 291 exactly 4 divisors: 1, 3, 97, 291. 291's proper divisors total just 101, 190 short of 291, the deficient case most of 291's neighbors share too. 291 has a digit sum of 12; for 291, the digital root works out to 3. 291: 3 all divide 291 evenly, out of 2-12. 291 is 100100011 in binary and 123 in hex; as a Roman numeral it's CCXCI.