645303165217 has 2 divisors, whose sum is σ = 645303165218. Its totient is φ = 645303165216.

The previous prime is 645303165203. The next prime is 645303165289. The reversal of 645303165217 is 712561303546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 477910898721 + 167392266496 = 691311^2 + 409136^2 .

It is a cyclic number.

It is not a de Polignac number, because 645303165217 - 2³⁹ = 95547351329 is a prime.

It is not a weakly prime, because it can be changed into another prime (645303165817) 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, 322651582608 + 322651582609.

It is an arithmetic number, because the mean of its divisors is an integer number (322651582609).

Almost surely, 2^645303165217 is an apocalyptic number.

It is an amenable number.

645303165217 is a deficient number, since it is larger than the sum of its proper divisors (1).

645303165217 is an equidigital number, since it uses as much as digits as its factorization.

645303165217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 453600, while the sum is 43.

The spelling of 645303165217 in words is "six hundred forty-five billion, three hundred three million, one hundred sixty-five thousand, two hundred seventeen".