81031322592 has 384 divisors, whose sum is σ = 268461527040. Its totient is φ = 23752396800.

The previous prime is 81031322591. The next prime is 81031322627. The reversal of 81031322592 is 29522313018.

81031322592 is a `hidden beast` number, since 8 + 1 + 0 + 31 + 32 + 2 + 592 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81031322591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 35648368 + ... + 35650640.

It is an arithmetic number, because the mean of its divisors is an integer number (699118560).

Almost surely, 2^81031322592 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81031322592, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134230763520).

81031322592 is an abundant number, since it is smaller than the sum of its proper divisors (187430204448).

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

81031322592 is a wasteful number, since it uses less digits than its factorization.

81031322592 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2356 (or 2320 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 81031322592 in words is "eighty-one billion, thirty-one million, three hundred twenty-two thousand, five hundred ninety-two".