643933049 has 2 divisors, whose sum is σ = 643933050. Its totient is φ = 643933048.

The previous prime is 643932997. The next prime is 643933061. The reversal of 643933049 is 940339346.

643933049 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., 504811024 + 139122025 = 22468^2 + 11795^2 .

It is a cyclic number.

It is not a de Polignac number, because 643933049 - 2¹⁶ = 643867513 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 643932997 and 643933015.

It is not a weakly prime, because it can be changed into another prime (643933079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321966524 + 321966525.

It is an arithmetic number, because the mean of its divisors is an integer number (321966525).

Almost surely, 2^643933049 is an apocalyptic number.

It is an amenable number.

643933049 is a deficient number, since it is larger than the sum of its proper divisors (1).

643933049 is an equidigital number, since it uses as much as digits as its factorization.

643933049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 41.

The square root of 643933049 is about 25375.8359271178. The cubic root of 643933049 is about 863.5355840496.

The spelling of 643933049 in words is "six hundred forty-three million, nine hundred thirty-three thousand, forty-nine".