81599401868 has 24 divisors (see below), whose sum is σ = 147128063040. Its totient is φ = 39580112000.

The previous prime is 81599401867. The next prime is 81599401883. The reversal of 81599401868 is 86810499518.

It is not an unprimeable number, because it can be changed into a prime (81599401861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2143508 + ... + 2181243.

It is an arithmetic number, because the mean of its divisors is an integer number (6130335960).

Almost surely, 2^81599401868 is an apocalyptic number.

It is an amenable number.

81599401868 is a deficient number, since it is larger than the sum of its proper divisors (65528661172).

81599401868 is a wasteful number, since it uses less digits than its factorization.

81599401868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4324897 (or 4324895 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 59.

The spelling of 81599401868 in words is "eighty-one billion, five hundred ninety-nine million, four hundred one thousand, eight hundred sixty-eight".