Numbers / 189

The Number 189

189 is composite: factorization 3^3 × 7. That gives 189 exactly 8 divisors: 1, 3, 7, 9, 21, 27, 63, 189. 189's proper divisors total just 131, 58 short of 189, the deficient case most of 189's neighbors share too. 189 has a digit sum of 18; for 189, the digital root works out to 9. 189: 3, 7, 9 all divide 189 evenly, out of 2-12. 189 is 10111101 in binary and BD in hex; as a Roman numeral it's CLXXXIX.