18009859 has 8 divisors (see below), whose sum is σ = 20783360. Its totient is φ = 15286536.

The previous prime is 18009857. The next prime is 18009881. The reversal of 18009859 is 95890081.

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

It is a cyclic number.

It is not a de Polignac number, because 18009859 - 2¹ = 18009857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18009857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11769 + ... + 13210.

It is an arithmetic number, because the mean of its divisors is an integer number (2597920).

Almost surely, 2^18009859 is an apocalyptic number.

18009859 is a deficient number, since it is larger than the sum of its proper divisors (2773501).

18009859 is a wasteful number, since it uses less digits than its factorization.

18009859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25089.

The product of its (nonzero) digits is 25920, while the sum is 40.

The square root of 18009859 is about 4243.8024223566. The cubic root of 18009859 is about 262.1219786311.

The spelling of 18009859 in words is "eighteen million, nine thousand, eight hundred fifty-nine".