643448436941 has 2 divisors, whose sum is σ = 643448436942. Its totient is φ = 643448436940.

The previous prime is 643448436929. The next prime is 643448436947. The reversal of 643448436941 is 149634844346.

643448436941 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 can be written as a sum of positive squares in only one way, i.e., 624014682916 + 19433754025 = 789946^2 + 139405^2 .

It is a cyclic number.

It is not a de Polignac number, because 643448436941 - 2¹⁴ = 643448420557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643448436947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321724218470 + 321724218471.

It is an arithmetic number, because the mean of its divisors is an integer number (321724218471).

Almost surely, 2^643448436941 is an apocalyptic number.

It is an amenable number.

643448436941 is a deficient number, since it is larger than the sum of its proper divisors (1).

643448436941 is an equidigital number, since it uses as much as digits as its factorization.

643448436941 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23887872, while the sum is 56.

The spelling of 643448436941 in words is "six hundred forty-three billion, four hundred forty-eight million, four hundred thirty-six thousand, nine hundred forty-one".