643423120663 has 2 divisors, whose sum is σ = 643423120664. Its totient is φ = 643423120662.

The previous prime is 643423120597. The next prime is 643423120667. The reversal of 643423120663 is 366021324346.

It is a happy number.

643423120663 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643423120663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643423120667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321711560331 + 321711560332.

It is an arithmetic number, because the mean of its divisors is an integer number (321711560332).

Almost surely, 2^643423120663 is an apocalyptic number.

643423120663 is a deficient number, since it is larger than the sum of its proper divisors (1).

643423120663 is an equidigital number, since it uses as much as digits as its factorization.

643423120663 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 40.

The spelling of 643423120663 in words is "six hundred forty-three billion, four hundred twenty-three million, one hundred twenty thousand, six hundred sixty-three".