81440570892 has 48 divisors (see below), whose sum is σ = 196610722560. Its totient is φ = 26206754112.

The previous prime is 81440570891. The next prime is 81440570899. The reversal of 81440570892 is 29807504418.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81440570891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2988633 + ... + 3015759.

It is an arithmetic number, because the mean of its divisors is an integer number (4096056720).

Almost surely, 2^81440570892 is an apocalyptic number.

It is an amenable number.

81440570892 is an abundant number, since it is smaller than the sum of its proper divisors (115170151668).

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

81440570892 is a wasteful number, since it uses less digits than its factorization.

81440570892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35790 (or 35788 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 48.

The spelling of 81440570892 in words is "eighty-one billion, four hundred forty million, five hundred seventy thousand, eight hundred ninety-two".