81590744589 has 4 divisors (see below), whose sum is σ = 108787659456. Its totient is φ = 54393829724.

The previous prime is 81590744551. The next prime is 81590744597. The reversal of 81590744589 is 98544709518.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81590744589 - 2²⁵ = 81557190157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81590744539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13598457429 + ... + 13598457434.

It is an arithmetic number, because the mean of its divisors is an integer number (27196914864).

Almost surely, 2^81590744589 is an apocalyptic number.

It is an amenable number.

81590744589 is a deficient number, since it is larger than the sum of its proper divisors (27196914867).

81590744589 is a wasteful number, since it uses less digits than its factorization.

81590744589 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27196914866.

The product of its (nonzero) digits is 14515200, while the sum is 60.

The spelling of 81590744589 in words is "eighty-one billion, five hundred ninety million, seven hundred forty-four thousand, five hundred eighty-nine".