668613899 has 2 divisors, whose sum is σ = 668613900. Its totient is φ = 668613898.

The previous prime is 668613889. The next prime is 668613917. The reversal of 668613899 is 998316866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668613899 - 2¹² = 668609803 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (668613889) 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, 334306949 + 334306950.

It is an arithmetic number, because the mean of its divisors is an integer number (334306950).

Almost surely, 2^668613899 is an apocalyptic number.

668613899 is a deficient number, since it is larger than the sum of its proper divisors (1).

668613899 is an equidigital number, since it uses as much as digits as its factorization.

668613899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3359232, while the sum is 56.

The square root of 668613899 is about 25857.5694720134. The cubic root of 668613899 is about 874.4301700490.

The spelling of 668613899 in words is "six hundred sixty-eight million, six hundred thirteen thousand, eight hundred ninety-nine".