18368557 has 2 divisors, whose sum is σ = 18368558. Its totient is φ = 18368556.

The previous prime is 18368543. The next prime is 18368563. The reversal of 18368557 is 75586381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17547721 + 820836 = 4189^2 + 906^2 .

It is a cyclic number.

It is not a de Polignac number, because 18368557 - 2⁷ = 18368429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18368657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9184278 + 9184279.

It is an arithmetic number, because the mean of its divisors is an integer number (9184279).

Almost surely, 2^18368557 is an apocalyptic number.

It is an amenable number.

18368557 is a deficient number, since it is larger than the sum of its proper divisors (1).

18368557 is an equidigital number, since it uses as much as digits as its factorization.

18368557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 201600, while the sum is 43.

The square root of 18368557 is about 4285.8554571987. The cubic root of 18368557 is about 263.8507583556.

The spelling of 18368557 in words is "eighteen million, three hundred sixty-eight thousand, five hundred fifty-seven".