18431339 has 2 divisors, whose sum is σ = 18431340. Its totient is φ = 18431338.

The previous prime is 18431323. The next prime is 18431341. The reversal of 18431339 is 93313481.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (93313481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18431339 - 2⁴ = 18431323 is a prime.

Together with 18431341, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18431239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9215669 + 9215670.

It is an arithmetic number, because the mean of its divisors is an integer number (9215670).

Almost surely, 2^18431339 is an apocalyptic number.

18431339 is a deficient number, since it is larger than the sum of its proper divisors (1).

18431339 is an equidigital number, since it uses as much as digits as its factorization.

18431339 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 32.

The square root of 18431339 is about 4293.1735348108. The cubic root of 18431339 is about 264.1510222148.

The spelling of 18431339 in words is "eighteen million, four hundred thirty-one thousand, three hundred thirty-nine".