81599460568 has 8 divisors (see below), whose sum is σ = 152998988580. Its totient is φ = 40799730280.

The previous prime is 81599460557. The next prime is 81599460583. The reversal of 81599460568 is 86506499518.

It is a tau number, because it is divible by the number of its divisors (8).

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 as a sum of consecutive naturals, namely, 5099966278 + ... + 5099966293.

Almost surely, 2^81599460568 is an apocalyptic number.

It is an amenable number.

81599460568 is a deficient number, since it is larger than the sum of its proper divisors (71399528012).

81599460568 is a wasteful number, since it uses less digits than its factorization.

81599460568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10199932577 (or 10199932573 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 61.

The spelling of 81599460568 in words is "eighty-one billion, five hundred ninety-nine million, four hundred sixty thousand, five hundred sixty-eight".