643241321 has 2 divisors, whose sum is σ = 643241322. Its totient is φ = 643241320.

The previous prime is 643241317. The next prime is 643241341. The reversal of 643241321 is 123142346.

643241321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 642115600 + 1125721 = 25340^2 + 1061^2 .

It is a cyclic number.

It is not a de Polignac number, because 643241321 - 2² = 643241317 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643241311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321620660 + 321620661.

It is an arithmetic number, because the mean of its divisors is an integer number (321620661).

Almost surely, 2^643241321 is an apocalyptic number.

It is an amenable number.

643241321 is a deficient number, since it is larger than the sum of its proper divisors (1).

643241321 is an equidigital number, since it uses as much as digits as its factorization.

643241321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 26.

The square root of 643241321 is about 25362.2026054521. The cubic root of 643241321 is about 863.2262631968.

Adding to 643241321 its reverse (123142346), we get a palindrome (766383667).

The spelling of 643241321 in words is "six hundred forty-three million, two hundred forty-one thousand, three hundred twenty-one".