Q: Is 640,628 a Prime Number?
A: No, 640,628 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 640628 can be evenly divided by 1 2 4 17 34 68 9,421 18,842 37,684 160,157 320,314 and 640,628, with no remainder.
Since 640,628 cannot be divided by just 1 and 640,628, it is not a prime number.