The number 629,640 can be evenly divided by 1 2 3 4 5 6 8 9 10 11 12 15 18 20 22 24 27 30 33 36 40 44 45 53 54 55 60 66 72 88 90 99 106 108 110 120 132 135 159 165 180 198 212 216 220 264 265 270 297 318 330 360 396 424 440 477 495 530 540 583 594 636 660 792 795 954 990 1,060 1,080 1,166 1,188 1,272 1,320 1,431 1,485 1,590 1,749 1,908 1,980 2,120 2,332 2,376 2,385 2,862 2,915 2,970 3,180 3,498 3,816 3,960 4,664 4,770 5,247 5,724 5,830 5,940 6,360 6,996 7,155 8,745 9,540 10,494 11,448 11,660 11,880 13,992 14,310 15,741 17,490 19,080 20,988 23,320 26,235 28,620 31,482 34,980 41,976 52,470 57,240 62,964 69,960 78,705 104,940 125,928 157,410 209,880 314,820 and 629,640, with no remainder.
Since 629,640 cannot be divided by just 1 and 629,640, it is a composite number.