668704741321 has 2 divisors, whose sum is σ = 668704741322. Its totient is φ = 668704741320.

The previous prime is 668704741259. The next prime is 668704741333. The reversal of 668704741321 is 123147407866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 541601796096 + 127102945225 = 735936^2 + 356515^2 .

It is a cyclic number.

It is not a de Polignac number, because 668704741321 - 2¹¹ = 668704739273 is a prime.

It is not a weakly prime, because it can be changed into another prime (668704741721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334352370660 + 334352370661.

It is an arithmetic number, because the mean of its divisors is an integer number (334352370661).

Almost surely, 2^668704741321 is an apocalyptic number.

It is an amenable number.

668704741321 is a deficient number, since it is larger than the sum of its proper divisors (1).

668704741321 is an equidigital number, since it uses as much as digits as its factorization.

668704741321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1354752, while the sum is 49.

The spelling of 668704741321 in words is "six hundred sixty-eight billion, seven hundred four million, seven hundred forty-one thousand, three hundred twenty-one".