81395831252 has 12 divisors (see below), whose sum is σ = 142459943136. Its totient is φ = 40692990360.

The previous prime is 81395831233. The next prime is 81395831263. The reversal of 81395831252 is 25213859318.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 81395831197 and 81395831206.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1194008 + ... + 1260335.

It is an arithmetic number, because the mean of its divisors is an integer number (11871661928).

Almost surely, 2^81395831252 is an apocalyptic number.

It is an amenable number.

81395831252 is a deficient number, since it is larger than the sum of its proper divisors (61064111884).

81395831252 is a wasteful number, since it uses less digits than its factorization.

81395831252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2462638 (or 2462636 counting only the distinct ones).

The product of its digits is 518400, while the sum is 47.

The spelling of 81395831252 in words is "eighty-one billion, three hundred ninety-five million, eight hundred thirty-one thousand, two hundred fifty-two".