Q: Is 643,439 a Prime Number?
A: Yes, 643,439 is a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 643439 can be evenly divided by 1 and 643,439, with no remainder.
Since 643,439 can be divided by just 1 and 643,439, it is a prime number.