18117840239 has 4 divisors (see below), whose sum is σ = 18153435720. Its totient is φ = 18082244760.

The previous prime is 18117840217. The next prime is 18117840259. The reversal of 18117840239 is 93204871181.

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

It is a cyclic number.

It is not a de Polignac number, because 18117840239 - 2⁸ = 18117839983 is a prime.

It is a super-2 number, since 2×18117840239² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18117840239.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18117840259) 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, 17796977 + ... + 17797994.

It is an arithmetic number, because the mean of its divisors is an integer number (4538358930).

Almost surely, 2^18117840239 is an apocalyptic number.

18117840239 is a deficient number, since it is larger than the sum of its proper divisors (35595481).

18117840239 is an equidigital number, since it uses as much as digits as its factorization.

18117840239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35595480.

The product of its (nonzero) digits is 96768, while the sum is 44.

The spelling of 18117840239 in words is "eighteen billion, one hundred seventeen million, eight hundred forty thousand, two hundred thirty-nine".