Q: Is 720,640 a Prime Number?
A: No, 720,640 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 720640 can be evenly divided by 1 2 4 5 8 10 16 20 32 40 64 80 128 160 256 320 563 640 1,126 1,280 2,252 2,815 4,504 5,630 9,008 11,260 18,016 22,520 36,032 45,040 72,064 90,080 144,128 180,160 360,320 and 720,640, with no remainder.
Since 720,640 cannot be divided by just 1 and 720,640, it is not a prime number.