Q: Is 399,221 a Prime Number?
A: Yes, 399,221 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 399221 can be evenly divided by 1 and 399,221, with no remainder.
Since 399,221 can be divided by just 1 and 399,221, it is a prime number.