7218813 has 16 divisors (see below), whose sum is σ = 11041280. Its totient is φ = 4109616.

The previous prime is 7218793. The next prime is 7218817. The reversal of 7218813 is 3188127.

It is a happy number.

It is not a de Polignac number, because 7218813 - 2⁶ = 7218749 is a prime.

It is a super-2 number, since 2×7218813² = 104222522257938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7218817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7506 + ... + 8412.

It is an arithmetic number, because the mean of its divisors is an integer number (690080).

Almost surely, 2^7218813 is an apocalyptic number.

It is an amenable number.

7218813 is a deficient number, since it is larger than the sum of its proper divisors (3822467).

7218813 is a wasteful number, since it uses less digits than its factorization.

7218813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1296.

The product of its digits is 2688, while the sum is 30.

The square root of 7218813 is about 2686.7848816011. The cubic root of 7218813 is about 193.2659135377.

The spelling of 7218813 in words is "seven million, two hundred eighteen thousand, eight hundred thirteen".