81252831 has 12 divisors (see below), whose sum is σ = 119081816. Its totient is φ = 49243920.

The previous prime is 81252827. The next prime is 81252839. The reversal of 81252831 is 13825218.

It is not a de Polignac number, because 81252831 - 2² = 81252827 is a prime.

It is a super-2 number, since 2×81252831² = 13204045091029122, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81252839) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 111556 + ... + 112281.

Almost surely, 2^81252831 is an apocalyptic number.

81252831 is a deficient number, since it is larger than the sum of its proper divisors (37828985).

81252831 is a wasteful number, since it uses less digits than its factorization.

81252831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223862 (or 223851 counting only the distinct ones).

The product of its digits is 3840, while the sum is 30.

The square root of 81252831 is about 9014.0352229176. The cubic root of 81252831 is about 433.1245830180.

The spelling of 81252831 in words is "eighty-one million, two hundred fifty-two thousand, eight hundred thirty-one".