668381671 has 2 divisors, whose sum is σ = 668381672. Its totient is φ = 668381670.

The previous prime is 668381641. The next prime is 668381683. The reversal of 668381671 is 176183866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 668381671 - 2⁷ = 668381543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668381611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334190835 + 334190836.

It is an arithmetic number, because the mean of its divisors is an integer number (334190836).

Almost surely, 2^668381671 is an apocalyptic number.

668381671 is a deficient number, since it is larger than the sum of its proper divisors (1).

668381671 is an equidigital number, since it uses as much as digits as its factorization.

668381671 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 46.

The square root of 668381671 is about 25853.0785594289. The cubic root of 668381671 is about 874.3289204416.

The spelling of 668381671 in words is "six hundred sixty-eight million, three hundred eighty-one thousand, six hundred seventy-one".