668223710509 has 2 divisors, whose sum is σ = 668223710510. Its totient is φ = 668223710508.

The previous prime is 668223710489. The next prime is 668223710519. The reversal of 668223710509 is 905017322866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 341207856900 + 327015853609 = 584130^2 + 571853^2 .

It is a cyclic number.

It is not a de Polignac number, because 668223710509 - 2⁷ = 668223710381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668223710519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334111855254 + 334111855255.

It is an arithmetic number, because the mean of its divisors is an integer number (334111855255).

Almost surely, 2^668223710509 is an apocalyptic number.

It is an amenable number.

668223710509 is a deficient number, since it is larger than the sum of its proper divisors (1).

668223710509 is an equidigital number, since it uses as much as digits as its factorization.

668223710509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1088640, while the sum is 49.

The spelling of 668223710509 in words is "six hundred sixty-eight billion, two hundred twenty-three million, seven hundred ten thousand, five hundred nine".