Numbers / 625

The Number 625

625 is composite: factorization 5^4. That gives 625 exactly 5 divisors: 1, 5, 25, 125, 625. 625's proper divisors total just 156, 469 short of 625, the deficient case most of 625's neighbors share too. 625 is also a perfect square, since 25² = 625. 625 has a digit sum of 13; for 625, the digital root works out to 4. 625: 5 all divide 625 evenly, out of 2-12. 625 is 1001110001 in binary and 271 in hex; as a Roman numeral it's DCXXV.