81040404008 has 16 divisors (see below), whose sum is σ = 151953859680. Its totient is φ = 40519374768.

The previous prime is 81040404007. The next prime is 81040404043. The reversal of 81040404008 is 80040404018.

It is not an unprimeable number, because it can be changed into a prime (81040404007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 573935 + ... + 701057.

It is an arithmetic number, because the mean of its divisors is an integer number (9497116230).

Almost surely, 2^81040404008 is an apocalyptic number.

It is an amenable number.

81040404008 is a deficient number, since it is larger than the sum of its proper divisors (70913455672).

81040404008 is a wasteful number, since it uses less digits than its factorization.

81040404008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206816 (or 206812 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 29.

The spelling of 81040404008 in words is "eighty-one billion, forty million, four hundred four thousand, eight".