Numbers / 166

The Number 166

166 is composite: factorization 2 × 83. That gives 166 exactly 4 divisors: 1, 2, 83, 166. 166's proper divisors total just 86, 80 short of 166, the deficient case most of 166's neighbors share too. 166 has a digit sum of 13; for 166, the digital root works out to 4. 166: 2 all divide 166 evenly, out of 2-12. 166 is 10100110 in binary and A6 in hex; as a Roman numeral it's CLXVI.