7218 has 12 divisors (see below), whose sum is σ = 15678. Its totient is φ = 2400.

The previous prime is 7213. The next prime is 7219. The reversal of 7218 is 8127.

It can be written as a sum of positive squares in only one way, i.e., 3969 + 3249 = 63^2 + 57^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 401 = 7218 / (7 + 2 + 1 + 8).

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 7218.

It is not an unprimeable number, because it can be changed into a prime (7211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 183 + ... + 218.

7218 is an abundant number, since it is smaller than the sum of its proper divisors (8460).

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

7218 is a wasteful number, since it uses less digits than its factorization.

7218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409 (or 406 counting only the distinct ones).

The product of its digits is 112, while the sum is 18.

The square root of 7218 is about 84.9588135510. The cubic root of 7218 is about 19.3258657909.

Subtracting 7218 from its reverse (8127), we obtain a palindrome (909).

It can be divided in two parts, 721 and 8, that added together give a 6-th power (729 = 3⁶).

The spelling of 7218 in words is "seven thousand, two hundred eighteen".