81371808574 has 16 divisors (see below), whose sum is σ = 139502268288. Its totient is φ = 34871697432.

The previous prime is 81371808523. The next prime is 81371808587. The reversal of 81371808574 is 47580817318.

It is a congruent number.

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, 116629 + ... + 419935.

It is an arithmetic number, because the mean of its divisors is an integer number (8718891768).

Almost surely, 2^81371808574 is an apocalyptic number.

81371808574 is a deficient number, since it is larger than the sum of its proper divisors (58130459714).

81371808574 is a wasteful number, since it uses less digits than its factorization.

81371808574 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322479.

The product of its (nonzero) digits is 1505280, while the sum is 52.

The spelling of 81371808574 in words is "eighty-one billion, three hundred seventy-one million, eight hundred eight thousand, five hundred seventy-four".