643568865341 has 2 divisors, whose sum is σ = 643568865342. Its totient is φ = 643568865340.

The previous prime is 643568865311. The next prime is 643568865347. The reversal of 643568865341 is 143568865346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 532827002500 + 110741862841 = 729950^2 + 332779^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643568865341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643568865347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321784432670 + 321784432671.

It is an arithmetic number, because the mean of its divisors is an integer number (321784432671).

Almost surely, 2^643568865341 is an apocalyptic number.

It is an amenable number.

643568865341 is a deficient number, since it is larger than the sum of its proper divisors (1).

643568865341 is an equidigital number, since it uses as much as digits as its factorization.

643568865341 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 49766400, while the sum is 59.

The spelling of 643568865341 in words is "six hundred forty-three billion, five hundred sixty-eight million, eight hundred sixty-five thousand, three hundred forty-one".