18090685 has 4 divisors (see below), whose sum is σ = 21708828. Its totient is φ = 14472544.

The previous prime is 18090643. The next prime is 18090689. The reversal of 18090685 is 58609081.

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 11215801 + 6874884 = 3349^2 + 2622^2 .

It is a cyclic number.

It is not a de Polignac number, because 18090685 - 2⁷ = 18090557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18090689) 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, 1809064 + ... + 1809073.

It is an arithmetic number, because the mean of its divisors is an integer number (5427207).

Almost surely, 2^18090685 is an apocalyptic number.

It is an amenable number.

18090685 is a deficient number, since it is larger than the sum of its proper divisors (3618143).

18090685 is an equidigital number, since it uses as much as digits as its factorization.

18090685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3618142.

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

The square root of 18090685 is about 4253.3145898229. The cubic root of 18090685 is about 262.5135170666.

The spelling of 18090685 in words is "eighteen million, ninety thousand, six hundred eighty-five".