Q: Is 643,409 a Prime Number?
A: No, 643,409 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 643409 can be evenly divided by 1 13 43 559 1,151 14,963 49,493 and 643,409, with no remainder.
Since 643,409 cannot be divided by just 1 and 643,409, it is not a prime number.