18818909 has 2 divisors, whose sum is σ = 18818910. Its totient is φ = 18818908.

The previous prime is 18818867. The next prime is 18818923. The reversal of 18818909 is 90981881.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10582009 + 8236900 = 3253^2 + 2870^2 .

It is a cyclic number.

It is not a de Polignac number, because 18818909 - 2¹² = 18814813 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18818909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18818929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9409454 + 9409455.

It is an arithmetic number, because the mean of its divisors is an integer number (9409455).

Almost surely, 2^18818909 is an apocalyptic number.

It is an amenable number.

18818909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18818909 is an equidigital number, since it uses as much as digits as its factorization.

18818909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 18818909 is about 4338.0766475479. The cubic root of 18818909 is about 265.9896965877.

The spelling of 18818909 in words is "eighteen million, eight hundred eighteen thousand, nine hundred nine".