18838189 has 4 divisors (see below), whose sum is σ = 19119424. Its totient is φ = 18556956.

The previous prime is 18838187. The next prime is 18838199. The reversal of 18838189 is 98183881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98183881 = 2341 ⋅41941.

It is a cyclic number.

It is not a de Polignac number, because 18838189 - 2¹ = 18838187 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 (18838181) 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, 140517 + ... + 140650.

It is an arithmetic number, because the mean of its divisors is an integer number (4779856).

Almost surely, 2^18838189 is an apocalyptic number.

It is an amenable number.

18838189 is a deficient number, since it is larger than the sum of its proper divisors (281235).

18838189 is an equidigital number, since it uses as much as digits as its factorization.

18838189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281234.

The product of its digits is 110592, while the sum is 46.

The square root of 18838189 is about 4340.2982616406. The cubic root of 18838189 is about 266.0805011970.

The spelling of 18838189 in words is "eighteen million, eight hundred thirty-eight thousand, one hundred eighty-nine".