Q: Is 688,540 a Prime Number?
A: No, 688,540 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 688540 can be evenly divided by 1 2 4 5 10 20 173 199 346 398 692 796 865 995 1,730 1,990 3,460 3,980 34,427 68,854 137,708 172,135 344,270 and 688,540, with no remainder.
Since 688,540 cannot be divided by just 1 and 688,540, it is not a prime number.