81132925818 has 32 divisors (see below), whose sum is σ = 185502813696. Its totient is φ = 23173820208.

The previous prime is 81132925817. The next prime is 81132925843. The reversal of 81132925818 is 81852923118.

It is not an unprimeable number, because it can be changed into a prime (81132925817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 151096 + ... + 430227.

It is an arithmetic number, because the mean of its divisors is an integer number (5796962928).

Almost surely, 2^81132925818 is an apocalyptic number.

81132925818 is an abundant number, since it is smaller than the sum of its proper divisors (104369887878).

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

81132925818 is a wasteful number, since it uses less digits than its factorization.

81132925818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584658.

The product of its digits is 276480, while the sum is 48.

The spelling of 81132925818 in words is "eighty-one billion, one hundred thirty-two million, nine hundred twenty-five thousand, eight hundred eighteen".