81595866859518 has 64 divisors (see below), whose sum is σ = 178371498850560. Its totient is φ = 24678233472000.

The previous prime is 81595866859387. The next prime is 81595866859523.

81595866859518 is nontrivially palindromic in base 10.

It is a Smith number, since the sum of its digits (84) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 273764718 + ... + 274062606.

It is an arithmetic number, because the mean of its divisors is an integer number (2787054669540).

Almost surely, 2^{81595866859518} is an apocalyptic number.

81595866859518 is an abundant number, since it is smaller than the sum of its proper divisors (96775631991042).

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

81595866859518 is a wasteful number, since it uses less digits than its factorization.

81595866859518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305913.

The product of its digits is 7464960000, while the sum is 84.

The spelling of 81595866859518 in words is "eighty-one trillion, five hundred ninety-five billion, eight hundred sixty-six million, eight hundred fifty-nine thousand, five hundred eighteen".