Q: Is 221,564 a Prime Number?
A: No, 221,564 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 221564 can be evenly divided by 1 2 4 7 14 28 41 82 164 193 287 386 574 772 1,148 1,351 2,702 5,404 7,913 15,826 31,652 55,391 110,782 and 221,564, with no remainder.
Since 221,564 cannot be divided by just 1 and 221,564, it is not a prime number.