Numbers / 165

The Number 165

165 is composite: factorization 3 × 5 × 11. That gives 165 exactly 8 divisors: 1, 3, 5, 11, 15, 33, 55, 165. 165's proper divisors total just 123, 42 short of 165, the deficient case most of 165's neighbors share too. 165 has a digit sum of 12; for 165, the digital root works out to 3. 165: 3, 5, 11 all divide 165 evenly, out of 2-12. 165 is 10100101 in binary and A5 in hex; as a Roman numeral it's CLXV.