668674949 has 2 divisors, whose sum is σ = 668674950. Its totient is φ = 668674948.

The previous prime is 668674927. The next prime is 668674973. The reversal of 668674949 is 949476866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 630913924 + 37761025 = 25118^2 + 6145^2 .

It is a cyclic number.

It is not a de Polignac number, because 668674949 - 2¹² = 668670853 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668673949) 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, 334337474 + 334337475.

It is an arithmetic number, because the mean of its divisors is an integer number (334337475).

Almost surely, 2^668674949 is an apocalyptic number.

It is an amenable number.

668674949 is a deficient number, since it is larger than the sum of its proper divisors (1).

668674949 is an equidigital number, since it uses as much as digits as its factorization.

668674949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15676416, while the sum is 59.

The square root of 668674949 is about 25858.7499504520. The cubic root of 668674949 is about 874.4567834838.

The spelling of 668674949 in words is "six hundred sixty-eight million, six hundred seventy-four thousand, nine hundred forty-nine".