81089597799 has 24 divisors (see below), whose sum is σ = 139746247920. Its totient is φ = 46336912272.

The previous prime is 81089597791. The next prime is 81089597807. The reversal of 81089597799 is 99779598018.

It is an interprime number because it is at equal distance from previous prime (81089597791) and next prime (81089597807).

It is not a de Polignac number, because 81089597799 - 2³ = 81089597791 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81089597791) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30644784 + ... + 30647429.

It is an arithmetic number, because the mean of its divisors is an integer number (5822760330).

Almost surely, 2^81089597799 is an apocalyptic number.

81089597799 is a deficient number, since it is larger than the sum of its proper divisors (58656650121).

81089597799 is a wasteful number, since it uses less digits than its factorization.

81089597799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61292236 (or 61292223 counting only the distinct ones).

The product of its (nonzero) digits is 102876480, while the sum is 72.

The spelling of 81089597799 in words is "eighty-one billion, eighty-nine million, five hundred ninety-seven thousand, seven hundred ninety-nine".