10231991 has 16 divisors (see below), whose sum is σ = 12918528. Its totient is φ = 7872000.

The previous prime is 10231981. The next prime is 10231993. The reversal of 10231991 is 19913201.

It is a cyclic number.

It is not a de Polignac number, because 10231991 - 2⁶ = 10231927 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 10231991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10231993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5591 + ... + 7191.

It is an arithmetic number, because the mean of its divisors is an integer number (807408).

Almost surely, 2^10231991 is an apocalyptic number.

10231991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

10231991 is a deficient number, since it is larger than the sum of its proper divisors (2686537).

10231991 is a wasteful number, since it uses less digits than its factorization.

10231991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1702.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 10231991 is about 3198.7483489640. The cubic root of 10231991 is about 217.0967805752.

The spelling of 10231991 in words is "ten million, two hundred thirty-one thousand, nine hundred ninety-one".