231146991 has 6 divisors (see below), whose sum is σ = 333879000. Its totient is φ = 154097988.

The previous prime is 231146963. The next prime is 231147001. The reversal of 231146991 is 199641132.

It is a happy number.

It is not a de Polignac number, because 231146991 - 2⁵ = 231146959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231146911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12841491 + ... + 12841508.

It is an arithmetic number, because the mean of its divisors is an integer number (55646500).

Almost surely, 2^231146991 is an apocalyptic number.

231146991 is a deficient number, since it is larger than the sum of its proper divisors (102732009).

231146991 is a wasteful number, since it uses less digits than its factorization.

231146991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25683005 (or 25683002 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 231146991 is about 15203.5190334343. The cubic root of 231146991 is about 613.7093615755.

The spelling of 231146991 in words is "two hundred thirty-one million, one hundred forty-six thousand, nine hundred ninety-one".