646401317 has 2 divisors, whose sum is σ = 646401318. Its totient is φ = 646401316.

The previous prime is 646401289. The next prime is 646401331. The reversal of 646401317 is 713104646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 439070116 + 207331201 = 20954^2 + 14399^2 .

It is a cyclic number.

It is not a de Polignac number, because 646401317 - 2⁸ = 646401061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646401347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323200658 + 323200659.

It is an arithmetic number, because the mean of its divisors is an integer number (323200659).

Almost surely, 2^646401317 is an apocalyptic number.

It is an amenable number.

646401317 is a deficient number, since it is larger than the sum of its proper divisors (1).

646401317 is an equidigital number, since it uses as much as digits as its factorization.

646401317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 646401317 is about 25424.4236316185. The cubic root of 646401317 is about 864.6375203924.

The spelling of 646401317 in words is "six hundred forty-six million, four hundred one thousand, three hundred seventeen".