18408589 has 4 divisors (see below), whose sum is σ = 18475324. Its totient is φ = 18341856.

The previous prime is 18408583. The next prime is 18408613. The reversal of 18408589 is 98580481.

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 3392964 + 15015625 = 1842^2 + 3875^2 .

It is a cyclic number.

It is not a de Polignac number, because 18408589 - 2³ = 18408581 is a prime.

It is a super-2 number, since 2×18408589² = 677752297941842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18408581) 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, 32952 + ... + 33505.

It is an arithmetic number, because the mean of its divisors is an integer number (4618831).

Almost surely, 2^18408589 is an apocalyptic number.

It is an amenable number.

18408589 is a deficient number, since it is larger than the sum of its proper divisors (66735).

18408589 is an equidigital number, since it uses as much as digits as its factorization.

18408589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66734.

The product of its (nonzero) digits is 92160, while the sum is 43.

The square root of 18408589 is about 4290.5231615737. The cubic root of 18408589 is about 264.0422959858.

The spelling of 18408589 in words is "eighteen million, four hundred eight thousand, five hundred eighty-nine".