Q: Is 685,840 a Prime Number?
A: No, 685,840 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 685840 can be evenly divided by 1 2 4 5 8 10 16 20 40 80 8,573 17,146 34,292 42,865 68,584 85,730 137,168 171,460 342,920 and 685,840, with no remainder.
Since 685,840 cannot be divided by just 1 and 685,840, it is not a prime number.