643662125573 has 2 divisors, whose sum is σ = 643662125574. Its totient is φ = 643662125572.

The previous prime is 643662125497. The next prime is 643662125593. The reversal of 643662125573 is 375521266346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 528495558529 + 115166567044 = 726977^2 + 339362^2 .

It is a cyclic number.

It is not a de Polignac number, because 643662125573 - 2²⁶ = 643595016709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643662125593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321831062786 + 321831062787.

It is an arithmetic number, because the mean of its divisors is an integer number (321831062787).

Almost surely, 2^643662125573 is an apocalyptic number.

It is an amenable number.

643662125573 is a deficient number, since it is larger than the sum of its proper divisors (1).

643662125573 is an equidigital number, since it uses as much as digits as its factorization.

643662125573 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5443200, while the sum is 50.

The spelling of 643662125573 in words is "six hundred forty-three billion, six hundred sixty-two million, one hundred twenty-five thousand, five hundred seventy-three".