18404609 has 2 divisors, whose sum is σ = 18404610. Its totient is φ = 18404608.

The previous prime is 18404579. The next prime is 18404627. The reversal of 18404609 is 90640481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9284209 + 9120400 = 3047^2 + 3020^2 .

It is a cyclic number.

It is not a de Polignac number, because 18404609 - 2²⁰ = 17356033 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18404689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9202304 + 9202305.

It is an arithmetic number, because the mean of its divisors is an integer number (9202305).

Almost surely, 2^18404609 is an apocalyptic number.

It is an amenable number.

18404609 is a deficient number, since it is larger than the sum of its proper divisors (1).

18404609 is an equidigital number, since it uses as much as digits as its factorization.

18404609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 18404609 is about 4290.0593235992. The cubic root of 18404609 is about 264.0232656646.

The spelling of 18404609 in words is "eighteen million, four hundred four thousand, six hundred nine".