18189812 has 24 divisors (see below), whose sum is σ = 32659200. Its totient is φ = 8861216.

The previous prime is 18189793. The next prime is 18189823. The reversal of 18189812 is 21898181.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 50489 + ... + 50847.

It is an arithmetic number, because the mean of its divisors is an integer number (1360800).

Almost surely, 2^18189812 is an apocalyptic number.

It is an amenable number.

18189812 is a deficient number, since it is larger than the sum of its proper divisors (14469388).

18189812 is a wasteful number, since it uses less digits than its factorization.

18189812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655 (or 653 counting only the distinct ones).

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

The square root of 18189812 is about 4264.9515823746. The cubic root of 18189812 is about 262.9921205117.

The spelling of 18189812 in words is "eighteen million, one hundred eighty-nine thousand, eight hundred twelve".