18031609 has 8 divisors (see below), whose sum is σ = 18862272. Its totient is φ = 17204880.

The previous prime is 18031603. The next prime is 18031613. The reversal of 18031609 is 90613081.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18031609 is a prime.

It is a super-3 number, since 3×18031609³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18031603) 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 in 7 ways as a sum of consecutive naturals, for example, 12447 + ... + 13819.

It is an arithmetic number, because the mean of its divisors is an integer number (2357784).

Almost surely, 2^18031609 is an apocalyptic number.

It is an amenable number.

18031609 is a deficient number, since it is larger than the sum of its proper divisors (830663).

18031609 is a wasteful number, since it uses less digits than its factorization.

18031609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1967.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 18031609 is about 4246.3642095327. The cubic root of 18031609 is about 262.2274552950.

The spelling of 18031609 in words is "eighteen million, thirty-one thousand, six hundred nine".