Q: Is 685,420 a Prime Number?
A: No, 685,420 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 685420 can be evenly divided by 1 2 4 5 10 20 43 86 172 215 430 797 860 1,594 3,188 3,985 7,970 15,940 34,271 68,542 137,084 171,355 342,710 and 685,420, with no remainder.
Since 685,420 cannot be divided by just 1 and 685,420, it is not a prime number.