Numbers / 989

The Number 989

989 is composite: factorization 23 × 43. That gives 989 exactly 4 divisors: 1, 23, 43, 989. 989's proper divisors total just 67, 922 short of 989, the deficient case most of 989's neighbors share too. 989 is also a palindrome, since 989 reads identically forwards and backwards. 989 has a digit sum of 26; for 989, the digital root works out to 8. 989 shares no factor with 2-12; 989's own divisors start beyond that range. 989 is 1111011101 in binary and 3DD in hex; as a Roman numeral it's CMLXXXIX.