Q: Is 671,643 a Prime Number?
A: No, 671,643 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 671643 can be evenly divided by 1 3 7 9 21 49 63 147 441 1,523 4,569 10,661 13,707 31,983 74,627 95,949 223,881 and 671,643, with no remainder.
Since 671,643 cannot be divided by just 1 and 671,643, it is not a prime number.