7218573809 has 2 divisors, whose sum is σ = 7218573810. Its totient is φ = 7218573808.

The previous prime is 7218573799. The next prime is 7218573811. The reversal of 7218573809 is 9083758127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6976926784 + 241647025 = 83528^2 + 15545^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7218573809 is a prime.

Together with 7218573811, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (7218573709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3609286904 + 3609286905.

It is an arithmetic number, because the mean of its divisors is an integer number (3609286905).

Almost surely, 2^7218573809 is an apocalyptic number.

It is an amenable number.

7218573809 is a deficient number, since it is larger than the sum of its proper divisors (1).

7218573809 is an equidigital number, since it uses as much as digits as its factorization.

7218573809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 846720, while the sum is 50.

The square root of 7218573809 is about 84962.1904672896. The cubic root of 7218573809 is about 1932.6377893114.

The spelling of 7218573809 in words is "seven billion, two hundred eighteen million, five hundred seventy-three thousand, eight hundred nine".