18318216 has 32 divisors (see below), whose sum is σ = 52338240. Its totient is φ = 5233728.

The previous prime is 18318191. The next prime is 18318217. The reversal of 18318216 is 61281381.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (18318217) 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, 54351 + ... + 54686.

It is an arithmetic number, because the mean of its divisors is an integer number (1635570).

Almost surely, 2^18318216 is an apocalyptic number.

It is an amenable number.

18318216 is an abundant number, since it is smaller than the sum of its proper divisors (34020024).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18318216 is a wasteful number, since it uses less digits than its factorization.

18318216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109053 (or 109049 counting only the distinct ones).

The product of its digits is 2304, while the sum is 30.

The square root of 18318216 is about 4279.9785046189. The cubic root of 18318216 is about 263.6095007256.

Adding to 18318216 its reverse (61281381), we get a palindrome (79599597).

The spelling of 18318216 in words is "eighteen million, three hundred eighteen thousand, two hundred sixteen".