Q: Is 666,880 a Prime Number?
A: No, 666,880 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 666880 can be evenly divided by 1 2 4 5 8 10 16 20 32 40 64 80 128 160 256 320 521 640 1,042 1,280 2,084 2,605 4,168 5,210 8,336 10,420 16,672 20,840 33,344 41,680 66,688 83,360 133,376 166,720 333,440 and 666,880, with no remainder.
Since 666,880 cannot be divided by just 1 and 666,880, it is not a prime number.