Q: Is 645,509 a Prime Number?
A: No, 645,509 is not a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 645509 can be evenly divided by 1 79 8,171 and 645,509, with no remainder.
Since 645,509 cannot be divided by just 1 and 645,509, it is not a prime number.