18136409 has 2 divisors, whose sum is σ = 18136410. Its totient is φ = 18136408.

The previous prime is 18136373. The next prime is 18136421. The reversal of 18136409 is 90463181.

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., 18088009 + 48400 = 4253^2 + 220^2 .

It is an emirp because it is prime and its reverse (90463181) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18136409 is a prime.

It is not a weakly prime, because it can be changed into another prime (18136439) 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, 9068204 + 9068205.

It is an arithmetic number, because the mean of its divisors is an integer number (9068205).

Almost surely, 2^18136409 is an apocalyptic number.

It is an amenable number.

18136409 is a deficient number, since it is larger than the sum of its proper divisors (1).

18136409 is an equidigital number, since it uses as much as digits as its factorization.

18136409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 18136409 is about 4258.6862997878. The cubic root of 18136409 is about 262.7344976358.

The spelling of 18136409 in words is "eighteen million, one hundred thirty-six thousand, four hundred nine".