7218864 has 30 divisors (see below), whose sum is σ = 20203196. Its totient is φ = 2406240.

The previous prime is 7218859. The next prime is 7218889. The reversal of 7218864 is 4688127.

It is a super-2 number, since 2×7218864² = 104223994900992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 24922 + ... + 25209.

Almost surely, 2^7218864 is an apocalyptic number.

It is an amenable number.

7218864 is an abundant number, since it is smaller than the sum of its proper divisors (12984332).

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

7218864 is a wasteful number, since it uses less digits than its factorization.

7218864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50145 (or 50136 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 7218864 is about 2686.7943724818. The cubic root of 7218864 is about 193.2663686697.

The spelling of 7218864 in words is "seven million, two hundred eighteen thousand, eight hundred sixty-four".