81507816204 has 36 divisors (see below), whose sum is σ = 191892707496. Its totient is φ = 26925362688.

The previous prime is 81507816193. The next prime is 81507816227. The reversal of 81507816204 is 40261870518.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10509192 + ... + 10516944.

It is an arithmetic number, because the mean of its divisors is an integer number (5330352986).

Almost surely, 2^81507816204 is an apocalyptic number.

It is an amenable number.

81507816204 is an abundant number, since it is smaller than the sum of its proper divisors (110384891292).

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

81507816204 is an equidigital number, since it uses as much as digits as its factorization.

81507816204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15626 (or 7871 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 42.

The spelling of 81507816204 in words is "eighty-one billion, five hundred seven million, eight hundred sixteen thousand, two hundred four".