9891

9891 is a natural number that falls between 9890 and 9892. In mathematics, it is an odd composite integer.

Its prime factorization is 9891 = 3^2 × 7 × 157, which implies there are 12 positive divisors: 1, 3, 7, 9, 21, 63, 157, 471, 1099, 1413, 3297, and 9891. The sum of all divisors is 16432, so the sum of proper divisors is 6541. Because this is less than 9891, the number is deficient rather than perfect or abundant. It is divisible by 9 (and thus by 3), which aligns with the digit sum of 9891 being 27.

In different numeral systems, 9891 can be represented as binary 10011010100011 and hexadecimal 0x26A3. It is not a prime, not a square or cube, and it does not belong to any widely notable small-named sequence beyond being a composite integer with the stated factorization.