Numbers / 393

The Number 393

393 is composite: factorization 3 × 131. That gives 393 exactly 4 divisors: 1, 3, 131, 393. 393's proper divisors total just 135, 258 short of 393, the deficient case most of 393's neighbors share too. 393 is also a palindrome, since 393 reads identically forwards and backwards. 393 has a digit sum of 15; for 393, the digital root works out to 6. 393: 3 all divide 393 evenly, out of 2-12. 393 is 110001001 in binary and 189 in hex; as a Roman numeral it's CCCXCIII.