18089609 has 4 divisors (see below), whose sum is σ = 18112260. Its totient is φ = 18066960.

The previous prime is 18089597. The next prime is 18089623. The reversal of 18089609 is 90698081.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10582009 + 7507600 = 3253^2 + 2740^2 .

It is a cyclic number.

It is not a de Polignac number, because 18089609 - 2¹² = 18085513 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18089009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10082 + ... + 11739.

It is an arithmetic number, because the mean of its divisors is an integer number (4528065).

Almost surely, 2^18089609 is an apocalyptic number.

It is an amenable number.

18089609 is a deficient number, since it is larger than the sum of its proper divisors (22651).

18089609 is an equidigital number, since it uses as much as digits as its factorization.

18089609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22650.

The product of its (nonzero) digits is 31104, while the sum is 41.

The square root of 18089609 is about 4253.1880983563. The cubic root of 18089609 is about 262.5083123596.

The spelling of 18089609 in words is "eighteen million, eighty-nine thousand, six hundred nine".