12189818 has 4 divisors (see below), whose sum is σ = 18284730. Its totient is φ = 6094908.

The previous prime is 12189817. The next prime is 12189847. The reversal of 12189818 is 81898121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11607649 + 582169 = 3407^2 + 763^2 .

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (12189817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3047453 + ... + 3047456.

Almost surely, 2^12189818 is an apocalyptic number.

12189818 is a deficient number, since it is larger than the sum of its proper divisors (6094912).

12189818 is an equidigital number, since it uses as much as digits as its factorization.

12189818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6094911.

The product of its digits is 9216, while the sum is 38.

The square root of 12189818 is about 3491.3919860136. The cubic root of 12189818 is about 230.1436909297.

The spelling of 12189818 in words is "twelve million, one hundred eighty-nine thousand, eight hundred eighteen".