6664321 has 2 divisors, whose sum is σ = 6664322. Its totient is φ = 6664320.

The previous prime is 6664309. The next prime is 6664351. The reversal of 6664321 is 1234666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6656400 + 7921 = 2580^2 + 89^2 .

It is a cyclic number.

It is not a de Polignac number, because 6664321 - 2⁹ = 6663809 is a prime.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 6664321.

It is not a weakly prime, because it can be changed into another prime (6664351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3332160 + 3332161.

It is an arithmetic number, because the mean of its divisors is an integer number (3332161).

Almost surely, 2^6664321 is an apocalyptic number.

It is an amenable number.

6664321 is a deficient number, since it is larger than the sum of its proper divisors (1).

6664321 is an equidigital number, since it uses as much as digits as its factorization.

6664321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 28.

The square root of 6664321 is about 2581.5346211120. The cubic root of 6664321 is about 188.1851296184.

Adding to 6664321 its reverse (1234666), we get a palindrome (7898987).

The spelling of 6664321 in words is "six million, six hundred sixty-four thousand, three hundred twenty-one".