Q: Is 671,721 a Prime Number?
A: No, 671,721 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 671721 can be evenly divided by 1 3 17 51 13,171 39,513 223,907 and 671,721, with no remainder.
Since 671,721 cannot be divided by just 1 and 671,721, it is not a prime number.