668964871 has 2 divisors, whose sum is σ = 668964872. Its totient is φ = 668964870.

The previous prime is 668964809. The next prime is 668964929. The reversal of 668964871 is 178469866.

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-668964871 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668964371) 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, 334482435 + 334482436.

It is an arithmetic number, because the mean of its divisors is an integer number (334482436).

Almost surely, 2^668964871 is an apocalyptic number.

668964871 is a deficient number, since it is larger than the sum of its proper divisors (1).

668964871 is an equidigital number, since it uses as much as digits as its factorization.

668964871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3483648, while the sum is 55.

The square root of 668964871 is about 25864.3552210373. The cubic root of 668964871 is about 874.5831466383.

The spelling of 668964871 in words is "six hundred sixty-eight million, nine hundred sixty-four thousand, eight hundred seventy-one".