18090859 has 4 divisors (see below), whose sum is σ = 18100800. Its totient is φ = 18080920.

The previous prime is 18090851. The next prime is 18090883. The reversal of 18090859 is 95809081.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18090859 - 2³ = 18090851 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18090851) 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 3 ways as a sum of consecutive naturals, for example, 1372 + ... + 6169.

It is an arithmetic number, because the mean of its divisors is an integer number (4525200).

Almost surely, 2^18090859 is an apocalyptic number.

18090859 is a deficient number, since it is larger than the sum of its proper divisors (9941).

18090859 is an equidigital number, since it uses as much as digits as its factorization.

18090859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9940.

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

The square root of 18090859 is about 4253.3350444093. The cubic root of 18090859 is about 262.5143587006.

The spelling of 18090859 in words is "eighteen million, ninety thousand, eight hundred fifty-nine".