664345403 has 2 divisors, whose sum is σ = 664345404. Its totient is φ = 664345402.

The previous prime is 664345391. The next prime is 664345417. The reversal of 664345403 is 304543466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664345403 - 2²⁰ = 663296827 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (664345483) 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, 332172701 + 332172702.

It is an arithmetic number, because the mean of its divisors is an integer number (332172702).

Almost surely, 2^664345403 is an apocalyptic number.

664345403 is a deficient number, since it is larger than the sum of its proper divisors (1).

664345403 is an equidigital number, since it uses as much as digits as its factorization.

664345403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 103680, while the sum is 35.

The square root of 664345403 is about 25774.8987000919. The cubic root of 664345403 is about 872.5653803876.

Adding to 664345403 its reverse (304543466), we get a palindrome (968888869).

The spelling of 664345403 in words is "six hundred sixty-four million, three hundred forty-five thousand, four hundred three".