Q: Is 668,721 a Prime Number?
A: No, 668,721 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 668721 can be evenly divided by 1 3 101 303 2,207 6,621 222,907 and 668,721, with no remainder.
Since 668,721 cannot be divided by just 1 and 668,721, it is not a prime number.