Q: Is 221,428 a Prime Number?
A: No, 221,428 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 221428 can be evenly divided by 1 2 4 197 281 394 562 788 1,124 55,357 110,714 and 221,428, with no remainder.
Since 221,428 cannot be divided by just 1 and 221,428, it is not a prime number.