81259473792 has 96 divisors (see below), whose sum is σ = 251085613320. Its totient is φ = 23216987136.

The previous prime is 81259473749. The next prime is 81259473853. The reversal of 81259473792 is 29737495218.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 2140503 + ... + 2178134.

Almost surely, 2^81259473792 is an apocalyptic number.

It is an amenable number.

81259473792 is an abundant number, since it is smaller than the sum of its proper divisors (169826139528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81259473792 is a wasteful number, since it uses less digits than its factorization.

81259473792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4318668 (or 4318649 counting only the distinct ones).

The product of its digits is 7620480, while the sum is 57.

The spelling of 81259473792 in words is "eighty-one billion, two hundred fifty-nine million, four hundred seventy-three thousand, seven hundred ninety-two".