664065173 has 2 divisors, whose sum is σ = 664065174. Its totient is φ = 664065172.

The previous prime is 664065161. The next prime is 664065187. The reversal of 664065173 is 371560466.

It is a happy number.

664065173 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 662444644 + 1620529 = 25738^2 + 1273^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664065173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664068173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332032586 + 332032587.

It is an arithmetic number, because the mean of its divisors is an integer number (332032587).

Almost surely, 2^664065173 is an apocalyptic number.

It is an amenable number.

664065173 is a deficient number, since it is larger than the sum of its proper divisors (1).

664065173 is an equidigital number, since it uses as much as digits as its factorization.

664065173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 664065173 is about 25769.4620238762. The cubic root of 664065173 is about 872.4426764527.

The spelling of 664065173 in words is "six hundred sixty-four million, sixty-five thousand, one hundred seventy-three".