81548599868 has 12 divisors (see below), whose sum is σ = 150221105160. Its totient is φ = 38628284112.

The previous prime is 81548599843. The next prime is 81548599879. The reversal of 81548599868 is 86899584518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 536503871 + ... + 536504022.

It is an arithmetic number, because the mean of its divisors is an integer number (12518425430).

Almost surely, 2^81548599868 is an apocalyptic number.

It is an amenable number.

81548599868 is a deficient number, since it is larger than the sum of its proper divisors (68672505292).

81548599868 is a wasteful number, since it uses less digits than its factorization.

81548599868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1073007916 (or 1073007914 counting only the distinct ones).

The product of its digits is 199065600, while the sum is 71.

The spelling of 81548599868 in words is "eighty-one billion, five hundred forty-eight million, five hundred ninety-nine thousand, eight hundred sixty-eight".