7218816 has 64 divisors (see below), whose sum is σ = 20930400. Its totient is φ = 2186240.

The previous prime is 7218793. The next prime is 7218817. The reversal of 7218816 is 6188127.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×7218816² = 104222608883712, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

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 7 ways as a sum of consecutive naturals, for example, 3370 + ... + 5078.

Almost surely, 2^7218816 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 7218816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10465200).

7218816 is an abundant number, since it is smaller than the sum of its proper divisors (13711584).

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

7218816 is a wasteful number, since it uses less digits than its factorization.

7218816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1737 (or 1725 counting only the distinct ones).

The product of its digits is 5376, while the sum is 33.

The square root of 7218816 is about 2686.7854398891. The cubic root of 7218816 is about 193.2659403103.

The spelling of 7218816 in words is "seven million, two hundred eighteen thousand, eight hundred sixteen".