664666913 has 2 divisors, whose sum is σ = 664666914. Its totient is φ = 664666912.

The previous prime is 664666889. The next prime is 664666943. The reversal of 664666913 is 319666466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 514064929 + 150601984 = 22673^2 + 12272^2 .

It is a cyclic number.

It is not a de Polignac number, because 664666913 - 2¹⁴ = 664650529 is a prime.

It is not a weakly prime, because it can be changed into another prime (664666943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332333456 + 332333457.

It is an arithmetic number, because the mean of its divisors is an integer number (332333457).

Almost surely, 2^664666913 is an apocalyptic number.

It is an amenable number.

664666913 is a deficient number, since it is larger than the sum of its proper divisors (1).

664666913 is an equidigital number, since it uses as much as digits as its factorization.

664666913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 47.

The square root of 664666913 is about 25781.1348276215. The cubic root of 664666913 is about 872.7061170439.

The spelling of 664666913 in words is "six hundred sixty-four million, six hundred sixty-six thousand, nine hundred thirteen".