18085609 has 2 divisors, whose sum is σ = 18085610. Its totient is φ = 18085608.

The previous prime is 18085597. The next prime is 18085631. The reversal of 18085609 is 90658081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14845609 + 3240000 = 3853^2 + 1800^2 .

It is an emirp because it is prime and its reverse (90658081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18085609 - 2⁷ = 18085481 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18085649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9042804 + 9042805.

It is an arithmetic number, because the mean of its divisors is an integer number (9042805).

Almost surely, 2^18085609 is an apocalyptic number.

It is an amenable number.

18085609 is a deficient number, since it is larger than the sum of its proper divisors (1).

18085609 is an equidigital number, since it uses as much as digits as its factorization.

18085609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 18085609 is about 4252.7178368662. The cubic root of 18085609 is about 262.4889621965.

The spelling of 18085609 in words is "eighteen million, eighty-five thousand, six hundred nine".