18169189 has 4 divisors (see below), whose sum is σ = 18418156. Its totient is φ = 17920224.

The previous prime is 18169171. The next prime is 18169201. The reversal of 18169189 is 98196181.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98196181 = 653 ⋅150377.

It can be written as a sum of positive squares in 2 ways, for example, as 6980164 + 11189025 = 2642^2 + 3345^2 .

It is a cyclic number.

It is not a de Polignac number, because 18169189 - 2⁷ = 18169061 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 (18169159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124374 + ... + 124519.

It is an arithmetic number, because the mean of its divisors is an integer number (4604539).

Almost surely, 2^18169189 is an apocalyptic number.

It is an amenable number.

18169189 is a deficient number, since it is larger than the sum of its proper divisors (248967).

18169189 is an equidigital number, since it uses as much as digits as its factorization.

18169189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248966.

The product of its digits is 31104, while the sum is 43.

The square root of 18169189 is about 4262.5331670264. The cubic root of 18169189 is about 262.8926923716.

The spelling of 18169189 in words is "eighteen million, one hundred sixty-nine thousand, one hundred eighty-nine".