Q: Is 688,400 a Prime Number?
A: No, 688,400 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 688400 can be evenly divided by 1 2 4 5 8 10 16 20 25 40 50 80 100 200 400 1,721 3,442 6,884 8,605 13,768 17,210 27,536 34,420 43,025 68,840 86,050 137,680 172,100 344,200 and 688,400, with no remainder.
Since 688,400 cannot be divided by just 1 and 688,400, it is not a prime number.