81136013772 has 48 divisors (see below), whose sum is σ = 207007363584. Its totient is φ = 24529608000.

The previous prime is 81136013759. The next prime is 81136013797. The reversal of 81136013772 is 27731063118.

It is a self number, because there is not a number n which added to its sum of digits gives 81136013772.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 656179 + ... + 769962.

It is an arithmetic number, because the mean of its divisors is an integer number (4312653408).

Almost surely, 2^81136013772 is an apocalyptic number.

It is an amenable number.

81136013772 is an abundant number, since it is smaller than the sum of its proper divisors (125871349812).

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

81136013772 is a wasteful number, since it uses less digits than its factorization.

81136013772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426590 (or 1426588 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 39.

The spelling of 81136013772 in words is "eighty-one billion, one hundred thirty-six million, thirteen thousand, seven hundred seventy-two".