Numbers / 553

The Number 553

553 is composite: factorization 7 × 79. That gives 553 exactly 4 divisors: 1, 7, 79, 553. 553's proper divisors total just 87, 466 short of 553, the deficient case most of 553's neighbors share too. 553 has a digit sum of 13; for 553, the digital root works out to 4. 553: 7 all divide 553 evenly, out of 2-12. 553 is 1000101001 in binary and 229 in hex; as a Roman numeral it's DLIII.