Q: Is 21,517,720 a Composite Number?

Why is 21,517,720 a composite number?

A composite number is a number that can be divided evenly by more numbers than 1 and itself. It is the opposite of a prime number.

The number 21,517,720 can be evenly divided by 1 2 4 5 7 8 10 14 20 28 31 35 37 40 56 62 67 70 74 124 134 140 148 155 185 217 248 259 268 280 296 310 335 370 434 469 518 536 620 670 740 868 938 1,036 1,085 1,147 1,240 1,295 1,340 1,480 1,736 1,876 2,072 2,077 2,170 2,294 2,345 2,479 2,590 2,680 3,752 4,154 4,340 4,588 4,690 4,958 5,180 5,735 8,029 8,308 8,680 9,176 9,380 9,916 10,360 10,385 11,470 12,395 14,539 16,058 16,616 17,353 18,760 19,832 20,770 22,940 24,790 29,078 32,116 34,706 40,145 41,540 45,880 49,580 58,156 64,232 69,412 72,695 76,849 80,290 83,080 86,765 99,160 116,312 138,824 145,390 153,698 160,580 173,530 290,780 307,396 321,160 347,060 384,245 537,943 581,560 614,792 694,120 768,490 1,075,886 1,536,980 2,151,772 2,689,715 3,073,960 4,303,544 5,379,430 10,758,860 and 21,517,720, with no remainder.

Since 21,517,720 cannot be divided by just 1 and 21,517,720, it is a composite number.

More Examples

• All positive natural numbers are either a prime number or a composite number (except the number 1, which is neither).