81610856514 has 48 divisors (see below), whose sum is σ = 199550070720. Its totient is φ = 23877782880.

The previous prime is 81610856513. The next prime is 81610856521. The reversal of 81610856514 is 41565801618.

81610856514 is a `hidden beast` number, since 81 + 6 + 1 + 0 + 8 + 56 + 514 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 81610856514.

It is not an unprimeable number, because it can be changed into a prime (81610856513) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7100742 + ... + 7112225.

It is an arithmetic number, because the mean of its divisors is an integer number (4157293140).

Almost surely, 2^81610856514 is an apocalyptic number.

81610856514 is an abundant number, since it is smaller than the sum of its proper divisors (117939214206).

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

81610856514 is a wasteful number, since it uses less digits than its factorization.

81610856514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14213015 (or 14213012 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 45.

The spelling of 81610856514 in words is "eighty-one billion, six hundred ten million, eight hundred fifty-six thousand, five hundred fourteen".