18133909 has 2 divisors, whose sum is σ = 18133910. Its totient is φ = 18133908.

The previous prime is 18133891. The next prime is 18133919. The reversal of 18133909 is 90933181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12229009 + 5904900 = 3497^2 + 2430^2 .

It is an emirp because it is prime and its reverse (90933181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18133909 - 2⁵ = 18133877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18133919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9066954 + 9066955.

It is an arithmetic number, because the mean of its divisors is an integer number (9066955).

Almost surely, 2^18133909 is an apocalyptic number.

It is an amenable number.

18133909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18133909 is an equidigital number, since it uses as much as digits as its factorization.

18133909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 18133909 is about 4258.3927719270. The cubic root of 18133909 is about 262.7224249330.

The spelling of 18133909 in words is "eighteen million, one hundred thirty-three thousand, nine hundred nine".