18338689 has 4 divisors (see below), whose sum is σ = 18684756. Its totient is φ = 17992624.

The previous prime is 18338681. The next prime is 18338693. The reversal of 18338689 is 98683381.

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 16265089 + 2073600 = 4033^2 + 1440^2 .

It is a cyclic number.

It is not a de Polignac number, because 18338689 - 2³ = 18338681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18338681) 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, 172954 + ... + 173059.

It is an arithmetic number, because the mean of its divisors is an integer number (4671189).

Almost surely, 2^18338689 is an apocalyptic number.

It is an amenable number.

18338689 is a deficient number, since it is larger than the sum of its proper divisors (346067).

18338689 is an equidigital number, since it uses as much as digits as its factorization.

18338689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346066.

The product of its digits is 248832, while the sum is 46.

The square root of 18338689 is about 4282.3695543472. The cubic root of 18338689 is about 263.7076701832.

The spelling of 18338689 in words is "eighteen million, three hundred thirty-eight thousand, six hundred eighty-nine".