18436009 has 2 divisors, whose sum is σ = 18436010. Its totient is φ = 18436008.

The previous prime is 18436003. The next prime is 18436021. The reversal of 18436009 is 90063481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10890000 + 7546009 = 3300^2 + 2747^2 .

It is an emirp because it is prime and its reverse (90063481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18436009 - 2³ = 18436001 is a prime.

It is not a weakly prime, because it can be changed into another prime (18436001) 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, 9218004 + 9218005.

It is an arithmetic number, because the mean of its divisors is an integer number (9218005).

Almost surely, 2^18436009 is an apocalyptic number.

It is an amenable number.

18436009 is a deficient number, since it is larger than the sum of its proper divisors (1).

18436009 is an equidigital number, since it uses as much as digits as its factorization.

18436009 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 31.

The square root of 18436009 is about 4293.7173870668. The cubic root of 18436009 is about 264.1733298924.

The spelling of 18436009 in words is "eighteen million, four hundred thirty-six thousand, nine".