81371808570 has 32 divisors (see below), whose sum is σ = 210314829312. Its totient is φ = 20029983552.

The previous prime is 81371808523. The next prime is 81371808587. The reversal of 81371808570 is 7580817318.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104322442 + ... + 104323221.

It is an arithmetic number, because the mean of its divisors is an integer number (6572338416).

Almost surely, 2^81371808570 is an apocalyptic number.

81371808570 is an abundant number, since it is smaller than the sum of its proper divisors (128943020742).

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

81371808570 is a wasteful number, since it uses less digits than its factorization.

81371808570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208645686.

The product of its (nonzero) digits is 376320, while the sum is 48.

The spelling of 81371808570 in words is "eighty-one billion, three hundred seventy-one million, eight hundred eight thousand, five hundred seventy".