Q: Is 643,859 a Prime Number?
A: Yes, 643,859 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 643859 can be evenly divided by 1 and 643,859, with no remainder.
Since 643,859 can be divided by just 1 and 643,859, it is a prime number.