18189844 has 24 divisors (see below), whose sum is σ = 33120360. Its totient is φ = 8730624.

The previous prime is 18189841. The next prime is 18189851. The reversal of 18189844 is 44898181.

It can be written as a sum of positive squares in 4 ways, for example, as 448900 + 17740944 = 670^2 + 4212^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18189844.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18189841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26692 + ... + 27364.

It is an arithmetic number, because the mean of its divisors is an integer number (1380015).

Almost surely, 2^18189844 is an apocalyptic number.

It is an amenable number.

18189844 is a deficient number, since it is larger than the sum of its proper divisors (14930516).

18189844 is a wasteful number, since it uses less digits than its factorization.

18189844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 939 (or 937 counting only the distinct ones).

The product of its digits is 73728, while the sum is 43.

The square root of 18189844 is about 4264.9553338810. The cubic root of 18189844 is about 262.9922747325.

The spelling of 18189844 in words is "eighteen million, one hundred eighty-nine thousand, eight hundred forty-four".