668045689 has 2 divisors, whose sum is σ = 668045690. Its totient is φ = 668045688.

The previous prime is 668045683. The next prime is 668045699. The reversal of 668045689 is 986540866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 649383289 + 18662400 = 25483^2 + 4320^2 .

It is a cyclic number.

It is not a de Polignac number, because 668045689 - 2⁵ = 668045657 is a prime.

It is not a weakly prime, because it can be changed into another prime (668045683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334022844 + 334022845.

It is an arithmetic number, because the mean of its divisors is an integer number (334022845).

Almost surely, 2^668045689 is an apocalyptic number.

It is an amenable number.

668045689 is a deficient number, since it is larger than the sum of its proper divisors (1).

668045689 is an equidigital number, since it uses as much as digits as its factorization.

668045689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2488320, while the sum is 52.

The square root of 668045689 is about 25846.5798317688. The cubic root of 668045689 is about 874.1823933758.

The spelling of 668045689 in words is "six hundred sixty-eight million, forty-five thousand, six hundred eighty-nine".