18418399 has 2 divisors, whose sum is σ = 18418400. Its totient is φ = 18418398.

The previous prime is 18418373. The next prime is 18418403. The reversal of 18418399 is 99381481.

It is a strong prime.

It is an emirp because it is prime and its reverse (99381481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18418399 - 2¹¹ = 18416351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18418339) 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, 9209199 + 9209200.

It is an arithmetic number, because the mean of its divisors is an integer number (9209200).

Almost surely, 2^18418399 is an apocalyptic number.

18418399 is a deficient number, since it is larger than the sum of its proper divisors (1).

18418399 is an equidigital number, since it uses as much as digits as its factorization.

18418399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 43.

The square root of 18418399 is about 4291.6662265372. Note that the first 3 decimals coincide. The cubic root of 18418399 is about 264.0891906707.

The spelling of 18418399 in words is "eighteen million, four hundred eighteen thousand, three hundred ninety-nine".