81310232 has 16 divisors (see below), whose sum is σ = 152552400. Its totient is φ = 40629600.

The previous prime is 81310231. The next prime is 81310237. The reversal of 81310232 is 23201318.

It is a super-2 number, since 2×81310232² = 13222707655787648, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81310231) 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 3 ways as a sum of consecutive naturals, for example, 22982 + ... + 26282.

It is an arithmetic number, because the mean of its divisors is an integer number (9534525).

Almost surely, 2^81310232 is an apocalyptic number.

It is an amenable number.

81310232 is a deficient number, since it is larger than the sum of its proper divisors (71242168).

81310232 is a wasteful number, since it uses less digits than its factorization.

81310232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6386 (or 6382 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 81310232 is about 9017.2186399133. The cubic root of 81310232 is about 433.2265525192.

The spelling of 81310232 in words is "eighty-one million, three hundred ten thousand, two hundred thirty-two".