Q: Is 221,603 a Prime Number?
A: Yes, 221,603 is a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 221603 can be evenly divided by 1 and 221,603, with no remainder.
Since 221,603 can be divided by just 1 and 221,603, it is a prime number.