664712223257321 has 2 divisors, whose sum is σ = 664712223257322. Its totient is φ = 664712223257320.

The previous prime is 664712223257309. The next prime is 664712223257393. The reversal of 664712223257321 is 123752322217466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 512620088443225 + 152092134814096 = 22641115^2 + 12332564^2 .

It is a cyclic number.

It is not a de Polignac number, because 664712223257321 - 2¹⁴ = 664712223240937 is a prime.

It is not a weakly prime, because it can be changed into another prime (664712223757321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332356111628660 + 332356111628661.

It is an arithmetic number, because the mean of its divisors is an integer number (332356111628661).

Almost surely, 2^{664712223257321} is an apocalyptic number.

It is an amenable number.

664712223257321 is a deficient number, since it is larger than the sum of its proper divisors (1).

664712223257321 is an equidigital number, since it uses as much as digits as its factorization.

664712223257321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10160640, while the sum is 53.

The spelling of 664712223257321 in words is "six hundred sixty-four trillion, seven hundred twelve billion, two hundred twenty-three million, two hundred fifty-seven thousand, three hundred twenty-one".