Numbers / 818

The Number 818

818 is composite: factorization 2 × 409. That gives 818 exactly 4 divisors: 1, 2, 409, 818. 818's proper divisors total just 412, 406 short of 818, the deficient case most of 818's neighbors share too. 818 is also a palindrome, since 818 reads identically forwards and backwards. 818 has a digit sum of 17; for 818, the digital root works out to 8. 818: 2 all divide 818 evenly, out of 2-12. 818 is 1100110010 in binary and 332 in hex; as a Roman numeral it's DCCCXVIII.