Numbers / 213

The Number 213

213 is composite: factorization 3 × 71. That gives 213 exactly 4 divisors: 1, 3, 71, 213. 213's proper divisors total just 75, 138 short of 213, the deficient case most of 213's neighbors share too. 213 has a digit sum of 6; for 213, the digital root works out to 6. 213: 3 all divide 213 evenly, out of 2-12. 213 is 11010101 in binary and D5 in hex; as a Roman numeral it's CCXIII.