18091589 has 2 divisors, whose sum is σ = 18091590. Its totient is φ = 18091588.

The previous prime is 18091573. The next prime is 18091607. The reversal of 18091589 is 98519081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14760964 + 3330625 = 3842^2 + 1825^2 .

It is an emirp because it is prime and its reverse (98519081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18091589 - 2⁴ = 18091573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18091529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9045794 + 9045795.

It is an arithmetic number, because the mean of its divisors is an integer number (9045795).

Almost surely, 2^18091589 is an apocalyptic number.

It is an amenable number.

18091589 is a deficient number, since it is larger than the sum of its proper divisors (1).

18091589 is an equidigital number, since it uses as much as digits as its factorization.

18091589 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 41.

The square root of 18091589 is about 4253.4208585561. The cubic root of 18091589 is about 262.5178896349.

The spelling of 18091589 in words is "eighteen million, ninety-one thousand, five hundred eighty-nine".