Q: Is 643,607 a Prime Number?
A: No, 643,607 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 643607 can be evenly divided by 1 751 857 and 643,607, with no remainder.
Since 643,607 cannot be divided by just 1 and 643,607, it is not a prime number.