18942239 has 2 divisors, whose sum is σ = 18942240. Its totient is φ = 18942238.

The previous prime is 18942223. The next prime is 18942241. The reversal of 18942239 is 93224981.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18942239 - 2⁴ = 18942223 is a prime.

Together with 18942241, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18942139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9471119 + 9471120.

It is an arithmetic number, because the mean of its divisors is an integer number (9471120).

Almost surely, 2^18942239 is an apocalyptic number.

18942239 is a deficient number, since it is larger than the sum of its proper divisors (1).

18942239 is an equidigital number, since it uses as much as digits as its factorization.

18942239 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 38.

The square root of 18942239 is about 4352.2682591954. The cubic root of 18942239 is about 266.5694876805.

The spelling of 18942239 in words is "eighteen million, nine hundred forty-two thousand, two hundred thirty-nine".