18090389 has 4 divisors (see below), whose sum is σ = 18531660. Its totient is φ = 17649120.

The previous prime is 18090379. The next prime is 18090409. The reversal of 18090389 is 98309081.

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 592900 + 17497489 = 770^2 + 4183^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18090389 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 (18090379) 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, 220574 + ... + 220655.

It is an arithmetic number, because the mean of its divisors is an integer number (4632915).

Almost surely, 2^18090389 is an apocalyptic number.

It is an amenable number.

18090389 is a deficient number, since it is larger than the sum of its proper divisors (441271).

18090389 is an equidigital number, since it uses as much as digits as its factorization.

18090389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441270.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 18090389 is about 4253.2797932889. The cubic root of 18090389 is about 262.5120853090.

The spelling of 18090389 in words is "eighteen million, ninety thousand, three hundred eighty-nine".