Q: Is 20,720 a Prime Number?
A: No, 20,720 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 20720 can be evenly divided by 1 2 4 5 7 8 10 14 16 20 28 35 37 40 56 70 74 80 112 140 148 185 259 280 296 370 518 560 592 740 1,036 1,295 1,480 2,072 2,590 2,960 4,144 5,180 10,360 and 20,720, with no remainder.
Since 20,720 cannot be divided by just 1 and 20,720, it is not a prime number.