18331320239 has 32 divisors (see below), whose sum is σ = 19796451840. Its totient is φ = 16941456000.

The previous prime is 18331320221. The next prime is 18331320247. The reversal of 18331320239 is 93202313381.

It is a cyclic number.

It is not a de Polignac number, because 18331320239 - 2⁸ = 18331319983 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18331320199 and 18331320208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18331325239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17441264 + ... + 17442314.

It is an arithmetic number, because the mean of its divisors is an integer number (618639120).

Almost surely, 2^18331320239 is an apocalyptic number.

18331320239 is a deficient number, since it is larger than the sum of its proper divisors (1465131601).

18331320239 is a wasteful number, since it uses less digits than its factorization.

18331320239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1391.

The product of its (nonzero) digits is 23328, while the sum is 35.

The spelling of 18331320239 in words is "eighteen billion, three hundred thirty-one million, three hundred twenty thousand, two hundred thirty-nine".