81136013764 has 36 divisors (see below), whose sum is σ = 162794506644. Its totient is φ = 35244598272.

The previous prime is 81136013759. The next prime is 81136013797. The reversal of 81136013764 is 46731063118.

It can be written as a sum of positive squares in 6 ways, for example, as 589032900 + 80546980864 = 24270^2 + 283808^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3518617 + ... + 3541600.

It is an arithmetic number, because the mean of its divisors is an integer number (4522069629).

Almost surely, 2^81136013764 is an apocalyptic number.

It is an amenable number.

81136013764 is an abundant number, since it is smaller than the sum of its proper divisors (81658492880).

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

81136013764 is a wasteful number, since it uses less digits than its factorization.

81136013764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7060264 (or 7060249 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 40.

The spelling of 81136013764 in words is "eighty-one billion, one hundred thirty-six million, thirteen thousand, seven hundred sixty-four".