81364237928 has 32 divisors (see below), whose sum is σ = 164504088000. Its totient is φ = 37600928640.

The previous prime is 81364237891. The next prime is 81364237961. The reversal of 81364237928 is 82973246318.

It is a self number, because there is not a number n which added to its sum of digits gives 81364237928.

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, 6521708 + ... + 6534171.

It is an arithmetic number, because the mean of its divisors is an integer number (5140752750).

Almost surely, 2^81364237928 is an apocalyptic number.

It is an amenable number.

81364237928 is an abundant number, since it is smaller than the sum of its proper divisors (83139850072).

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

81364237928 is a wasteful number, since it uses less digits than its factorization.

81364237928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13055945 (or 13055941 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 53.

The spelling of 81364237928 in words is "eighty-one billion, three hundred sixty-four million, two hundred thirty-seven thousand, nine hundred twenty-eight".