Q: Is 638,420 a Prime Number?
A: No, 638,420 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 638420 can be evenly divided by 1 2 4 5 10 20 137 233 274 466 548 685 932 1,165 1,370 2,330 2,740 4,660 31,921 63,842 127,684 159,605 319,210 and 638,420, with no remainder.
Since 638,420 cannot be divided by just 1 and 638,420, it is not a prime number.