81059392512 has 264 divisors, whose sum is σ = 270016920576. Its totient is φ = 22941425664.

The previous prime is 81059392481. The next prime is 81059392573. The reversal of 81059392512 is 21529395018.

81059392512 is a `hidden beast` number, since 8 + 1 + 0 + 593 + 9 + 2 + 51 + 2 = 666.

It is a super-2 number, since 2×81059392512² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6896913 + ... + 6908655.

Almost surely, 2^81059392512 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 81059392512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135008460288).

81059392512 is an abundant number, since it is smaller than the sum of its proper divisors (188957528064).

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

81059392512 is a wasteful number, since it uses less digits than its factorization.

81059392512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11883 (or 11862 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 45.

The spelling of 81059392512 in words is "eighty-one billion, fifty-nine million, three hundred ninety-two thousand, five hundred twelve".