Q: Is 256,391 a Prime Number?
A: Yes, 256,391 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 256391 can be evenly divided by 1 and 256,391, with no remainder.
Since 256,391 can be divided by just 1 and 256,391, it is a prime number.