18111689 has 4 divisors (see below), whose sum is σ = 18736260. Its totient is φ = 17487120.

The previous prime is 18111673. The next prime is 18111701. The reversal of 18111689 is 98611181.

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 15272464 + 2839225 = 3908^2 + 1685^2 .

It is a cyclic number.

It is not a de Polignac number, because 18111689 - 2⁴ = 18111673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18111629) 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, 312242 + ... + 312299.

It is an arithmetic number, because the mean of its divisors is an integer number (4684065).

Almost surely, 2^18111689 is an apocalyptic number.

It is an amenable number.

18111689 is a deficient number, since it is larger than the sum of its proper divisors (624571).

18111689 is an equidigital number, since it uses as much as digits as its factorization.

18111689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624570.

The product of its digits is 3456, while the sum is 35.

The square root of 18111689 is about 4255.7830066863. The cubic root of 18111689 is about 262.6150739611.

The spelling of 18111689 in words is "eighteen million, one hundred eleven thousand, six hundred eighty-nine".