643240342193 has 2 divisors, whose sum is σ = 643240342194. Its totient is φ = 643240342192.

The previous prime is 643240342163. The next prime is 643240342211. The reversal of 643240342193 is 391243042346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 557662445824 + 85577896369 = 746768^2 + 292537^2 .

It is a cyclic number.

It is not a de Polignac number, because 643240342193 - 2⁸ = 643240341937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643240342193.

It is not a weakly prime, because it can be changed into another prime (643240342163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321620171096 + 321620171097.

It is an arithmetic number, because the mean of its divisors is an integer number (321620171097).

Almost surely, 2^643240342193 is an apocalyptic number.

It is an amenable number.

643240342193 is a deficient number, since it is larger than the sum of its proper divisors (1).

643240342193 is an equidigital number, since it uses as much as digits as its factorization.

643240342193 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 373248, while the sum is 41.

The spelling of 643240342193 in words is "six hundred forty-three billion, two hundred forty million, three hundred forty-two thousand, one hundred ninety-three".