The number 807,840 can be evenly divided by 1 2 3 4 5 6 8 9 10 11 12 15 16 17 18 20 22 24 27 30 32 33 34 36 40 44 45 48 51 54 55 60 66 68 72 80 85 88 90 96 99 102 108 110 120 132 135 136 144 153 160 165 170 176 180 187 198 204 216 220 240 255 264 270 272 288 297 306 330 340 352 360 374 396 408 432 440 459 480 495 510 528 540 544 561 594 612 660 680 720 748 765 792 816 864 880 918 935 990 1,020 1,056 1,080 1,122 1,188 1,224 1,320 1,360 1,440 1,485 1,496 1,530 1,584 1,632 1,683 1,760 1,836 1,870 1,980 2,040 2,160 2,244 2,295 2,376 2,448 2,640 2,720 2,805 2,970 2,992 3,060 3,168 3,366 3,672 3,740 3,960 4,080 4,320 4,488 4,590 4,752 4,896 5,049 5,280 5,610 5,940 5,984 6,120 6,732 7,344 7,480 7,920 8,160 8,415 8,976 9,180 9,504 10,098 11,220 11,880 12,240 13,464 14,688 14,960 15,840 16,830 17,952 18,360 20,196 22,440 23,760 24,480 25,245 26,928 29,920 33,660 36,720 40,392 44,880 47,520 50,490 53,856 67,320 73,440 80,784 89,760 100,980 134,640 161,568 201,960 269,280 403,920 and 807,840, with no remainder.
Since 807,840 cannot be divided by just 1 and 807,840, it is a composite number.