643705343 has 2 divisors, whose sum is σ = 643705344. Its totient is φ = 643705342.

The previous prime is 643705331. The next prime is 643705379. The reversal of 643705343 is 343507346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643705343 - 2⁴ = 643705327 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643705303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321852671 + 321852672.

It is an arithmetic number, because the mean of its divisors is an integer number (321852672).

Almost surely, 2^643705343 is an apocalyptic number.

643705343 is a deficient number, since it is larger than the sum of its proper divisors (1).

643705343 is an equidigital number, since it uses as much as digits as its factorization.

643705343 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 35.

The square root of 643705343 is about 25371.3488604765. The cubic root of 643705343 is about 863.4337849489.

The spelling of 643705343 in words is "six hundred forty-three million, seven hundred five thousand, three hundred forty-three".