81589140239 has 4 divisors (see below), whose sum is σ = 81720948840. Its totient is φ = 81457331640.

The previous prime is 81589140221. The next prime is 81589140251. The reversal of 81589140239 is 93204198518.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81589140239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81589130239) 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, 65903372 + ... + 65904609.

It is an arithmetic number, because the mean of its divisors is an integer number (20430237210).

Almost surely, 2^81589140239 is an apocalyptic number.

81589140239 is a deficient number, since it is larger than the sum of its proper divisors (131808601).

81589140239 is a wasteful number, since it uses less digits than its factorization.

81589140239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131808600.

The product of its (nonzero) digits is 622080, while the sum is 50.

The spelling of 81589140239 in words is "eighty-one billion, five hundred eighty-nine million, one hundred forty thousand, two hundred thirty-nine".