Q: Is 21,560 a Prime Number?
A: No, 21,560 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 21560 can be evenly divided by 1 2 4 5 7 8 10 11 14 20 22 28 35 40 44 49 55 56 70 77 88 98 110 140 154 196 220 245 280 308 385 392 440 490 539 616 770 980 1,078 1,540 1,960 2,156 2,695 3,080 4,312 5,390 10,780 and 21,560, with no remainder.
Since 21,560 cannot be divided by just 1 and 21,560, it is not a prime number.