643071564991 has 2 divisors, whose sum is σ = 643071564992. Its totient is φ = 643071564990.

The previous prime is 643071564977. The next prime is 643071565027. The reversal of 643071564991 is 199465170346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643071564991 - 2²⁹ = 642534694079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643071564901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321535782495 + 321535782496.

It is an arithmetic number, because the mean of its divisors is an integer number (321535782496).

Almost surely, 2^643071564991 is an apocalyptic number.

643071564991 is a deficient number, since it is larger than the sum of its proper divisors (1).

643071564991 is an equidigital number, since it uses as much as digits as its factorization.

643071564991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4898880, while the sum is 55.

The spelling of 643071564991 in words is "six hundred forty-three billion, seventy-one million, five hundred sixty-four thousand, nine hundred ninety-one".