668405263 has 2 divisors, whose sum is σ = 668405264. Its totient is φ = 668405262.

The previous prime is 668405203. The next prime is 668405273. The reversal of 668405263 is 362504866.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668405263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668405203) 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, 334202631 + 334202632.

It is an arithmetic number, because the mean of its divisors is an integer number (334202632).

Almost surely, 2^668405263 is an apocalyptic number.

668405263 is a deficient number, since it is larger than the sum of its proper divisors (1).

668405263 is an equidigital number, since it uses as much as digits as its factorization.

668405263 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 207360, while the sum is 40.

The square root of 668405263 is about 25853.5348260156. The cubic root of 668405263 is about 874.3392074408.

The spelling of 668405263 in words is "six hundred sixty-eight million, four hundred five thousand, two hundred sixty-three".