81208420804 has 24 divisors (see below), whose sum is σ = 162428333760. Its totient is φ = 34801146336.

The previous prime is 81208420763. The next prime is 81208420819. The reversal of 81208420804 is 40802480218.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 332559 + ... + 522505.

It is an arithmetic number, because the mean of its divisors is an integer number (6767847240).

Almost surely, 2^81208420804 is an apocalyptic number.

It is an amenable number.

81208420804 is an abundant number, since it is smaller than the sum of its proper divisors (81219912956).

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

81208420804 is a wasteful number, since it uses less digits than its factorization.

81208420804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205227 (or 205225 counting only the distinct ones).

The product of its (nonzero) digits is 32768, while the sum is 37.

The spelling of 81208420804 in words is "eighty-one billion, two hundred eight million, four hundred twenty thousand, eight hundred four".