18644216 has 16 divisors (see below), whose sum is σ = 36163800. Its totient is φ = 9000544.

The previous prime is 18644203. The next prime is 18644233. The reversal of 18644216 is 61244681.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39950 + ... + 40413.

Almost surely, 2^18644216 is an apocalyptic number.

It is an amenable number.

18644216 is a deficient number, since it is larger than the sum of its proper divisors (17519584).

18644216 is a wasteful number, since it uses less digits than its factorization.

18644216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80398 (or 80394 counting only the distinct ones).

The product of its digits is 9216, while the sum is 32.

The square root of 18644216 is about 4317.8948574508. The cubic root of 18644216 is about 265.1640896636.

Adding to 18644216 its reverse (61244681), we get a palindrome (79888897).

The spelling of 18644216 in words is "eighteen million, six hundred forty-four thousand, two hundred sixteen".