7218216 has 48 divisors (see below), whose sum is σ = 20229300. Its totient is φ = 2322432.

The previous prime is 7218209. The next prime is 7218221. The reversal of 7218216 is 6128127.

It can be written as a sum of positive squares in 2 ways, for example, as 6502500 + 715716 = 2550^2 + 846^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 7218216.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 360 + ... + 3816.

Almost surely, 2^7218216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7218216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10114650).

7218216 is an abundant number, since it is smaller than the sum of its proper divisors (13011084).

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

7218216 is a wasteful number, since it uses less digits than its factorization.

7218216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3498 (or 3491 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 7218216 is about 2686.6737799740. The cubic root of 7218216 is about 193.2605856567.

The spelling of 7218216 in words is "seven million, two hundred eighteen thousand, two hundred sixteen".