18138959 has 2 divisors, whose sum is σ = 18138960. Its totient is φ = 18138958.

The previous prime is 18138947. The next prime is 18138971. The reversal of 18138959 is 95983181.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (18138947) and next prime (18138971).

It is a cyclic number.

It is not a de Polignac number, because 18138959 - 2⁴ = 18138943 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18138919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9069479 + 9069480.

It is an arithmetic number, because the mean of its divisors is an integer number (9069480).

Almost surely, 2^18138959 is an apocalyptic number.

18138959 is a deficient number, since it is larger than the sum of its proper divisors (1).

18138959 is an equidigital number, since it uses as much as digits as its factorization.

18138959 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 44.

The square root of 18138959 is about 4258.9856773650. The cubic root of 18138959 is about 262.7468106498.

The spelling of 18138959 in words is "eighteen million, one hundred thirty-eight thousand, nine hundred fifty-nine".