18320216 has 16 divisors (see below), whose sum is σ = 34432440. Its totient is φ = 9138240.

The previous prime is 18320209. The next prime is 18320221. The reversal of 18320216 is 61202381.

It is a junction number, because it is equal to n+sod(n) for n = 18320191 and 18320200.

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, 1151 + ... + 6161.

Almost surely, 2^18320216 is an apocalyptic number.

It is an amenable number.

18320216 is a deficient number, since it is larger than the sum of its proper divisors (16112224).

18320216 is a wasteful number, since it uses less digits than its factorization.

18320216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5474 (or 5470 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 18320216 is about 4280.2121442751. The cubic root of 18320216 is about 263.6190940873.

Adding to 18320216 its reverse (61202381), we get a palindrome (79522597).

The spelling of 18320216 in words is "eighteen million, three hundred twenty thousand, two hundred sixteen".