18318689 has 2 divisors, whose sum is σ = 18318690. Its totient is φ = 18318688.

The previous prime is 18318683. The next prime is 18318697. The reversal of 18318689 is 98681381.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18318400 + 289 = 4280^2 + 17^2 .

It is a cyclic number.

It is not a de Polignac number, because 18318689 - 2¹⁶ = 18253153 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18318683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9159344 + 9159345.

It is an arithmetic number, because the mean of its divisors is an integer number (9159345).

Almost surely, 2^18318689 is an apocalyptic number.

It is an amenable number.

18318689 is a deficient number, since it is larger than the sum of its proper divisors (1).

18318689 is an equidigital number, since it uses as much as digits as its factorization.

18318689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 44.

The square root of 18318689 is about 4280.0337615491. The cubic root of 18318689 is about 263.6117696187.

The spelling of 18318689 in words is "eighteen million, three hundred eighteen thousand, six hundred eighty-nine".