7218720 has 120 divisors (see below), whose sum is σ = 25521804. Its totient is φ = 1921536.

The previous prime is 7218713. The next prime is 7218721. The reversal of 7218720 is 278127.

It can be written as a sum of positive squares in 2 ways, for example, as 6533136 + 685584 = 2556^2 + 828^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (7218721) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12682 + ... + 13238.

Almost surely, 2^7218720 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 7218720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12760902).

7218720 is an abundant number, since it is smaller than the sum of its proper divisors (18303084).

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

7218720 is a wasteful number, since it uses less digits than its factorization.

7218720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584 (or 567 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 7218720 is about 2686.7675746145. The cubic root of 7218720 is about 193.2650835856.

The spelling of 7218720 in words is "seven million, two hundred eighteen thousand, seven hundred twenty".