18388369 has 2 divisors, whose sum is σ = 18388370. Its totient is φ = 18388368.

The previous prime is 18388319. The next prime is 18388411. The reversal of 18388369 is 96388381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18378369 + 10000 = 4287^2 + 100^2 .

It is a cyclic number.

It is not a de Polignac number, because 18388369 - 2¹¹ = 18386321 is a prime.

It is a super-2 number, since 2×18388369² = 676264228960322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18388319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9194184 + 9194185.

It is an arithmetic number, because the mean of its divisors is an integer number (9194185).

Almost surely, 2^18388369 is an apocalyptic number.

It is an amenable number.

18388369 is a deficient number, since it is larger than the sum of its proper divisors (1).

18388369 is an equidigital number, since it uses as much as digits as its factorization.

18388369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 46.

The square root of 18388369 is about 4288.1661581613. The cubic root of 18388369 is about 263.9455858544.

The spelling of 18388369 in words is "eighteen million, three hundred eighty-eight thousand, three hundred sixty-nine".