Q: Is 678,721 a Prime Number?
A: Yes, 678,721 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 678721 can be evenly divided by 1 and 678,721, with no remainder.
Since 678,721 can be divided by just 1 and 678,721, it is a prime number.