81642812804 has 24 divisors (see below), whose sum is σ = 164870928768. Its totient is φ = 34650069120.

The previous prime is 81642812777. The next prime is 81642812857. The reversal of 81642812804 is 40821824618.

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, 14151557 + ... + 14157324.

It is an arithmetic number, because the mean of its divisors is an integer number (6869622032).

Almost surely, 2^81642812804 is an apocalyptic number.

It is an amenable number.

81642812804 is an abundant number, since it is smaller than the sum of its proper divisors (83228115964).

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

81642812804 is a wasteful number, since it uses less digits than its factorization.

81642812804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28308995 (or 28308993 counting only the distinct ones).

The product of its (nonzero) digits is 196608, while the sum is 44.

The spelling of 81642812804 in words is "eighty-one billion, six hundred forty-two million, eight hundred twelve thousand, eight hundred four".