7218566 has 4 divisors (see below), whose sum is σ = 10827852. Its totient is φ = 3609282.

The previous prime is 7218559. The next prime is 7218569. The reversal of 7218566 is 6658127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6658127 = 7 ⋅951161.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7218569) by changing a digit.

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 as a sum of consecutive naturals, namely, 1804640 + ... + 1804643.

It is an arithmetic number, because the mean of its divisors is an integer number (2706963).

Almost surely, 2^7218566 is an apocalyptic number.

7218566 is a deficient number, since it is larger than the sum of its proper divisors (3609286).

7218566 is a wasteful number, since it uses less digits than its factorization.

7218566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3609285.

The product of its digits is 20160, while the sum is 35.

The square root of 7218566 is about 2686.7389154884. The cubic root of 7218566 is about 193.2637092407.

The spelling of 7218566 in words is "seven million, two hundred eighteen thousand, five hundred sixty-six".