81538168715 has 16 divisors (see below), whose sum is σ = 97999545600. Its totient is φ = 65128130400.

The previous prime is 81538168709. The next prime is 81538168729. The reversal of 81538168715 is 51786183518.

It is not a de Polignac number, because 81538168715 - 2²⁶ = 81471059851 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9477986 + ... + 9486584.

It is an arithmetic number, because the mean of its divisors is an integer number (6124971600).

Almost surely, 2^81538168715 is an apocalyptic number.

81538168715 is a deficient number, since it is larger than the sum of its proper divisors (16461376885).

81538168715 is a wasteful number, since it uses less digits than its factorization.

81538168715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11362.

The product of its digits is 1612800, while the sum is 53.

The spelling of 81538168715 in words is "eighty-one billion, five hundred thirty-eight million, one hundred sixty-eight thousand, seven hundred fifteen".