The number 6,420,600 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 20 24 25 27 29 30 36 40 41 45 50 54 58 60 72 75 82 87 90 100 108 116 120 123 135 145 150 164 174 180 200 205 216 225 232 246 261 270 290 300 328 348 360 369 410 435 450 492 522 540 580 600 615 675 696 725 738 783 820 870 900 984 1,025 1,044 1,080 1,107 1,160 1,189 1,230 1,305 1,350 1,450 1,476 1,566 1,640 1,740 1,800 1,845 2,050 2,088 2,175 2,214 2,378 2,460 2,610 2,700 2,900 2,952 3,075 3,132 3,480 3,567 3,690 3,915 4,100 4,350 4,428 4,756 4,920 5,220 5,400 5,535 5,800 5,945 6,150 6,264 6,525 7,134 7,380 7,830 8,200 8,700 8,856 9,225 9,512 10,440 10,701 11,070 11,890 12,300 13,050 14,268 14,760 15,660 17,400 17,835 18,450 19,575 21,402 22,140 23,780 24,600 26,100 27,675 28,536 29,725 31,320 32,103 35,670 36,900 39,150 42,804 44,280 47,560 52,200 53,505 55,350 59,450 64,206 71,340 73,800 78,300 85,608 89,175 107,010 110,700 118,900 128,412 142,680 156,600 160,515 178,350 214,020 221,400 237,800 256,824 267,525 321,030 356,700 428,040 535,050 642,060 713,400 802,575 1,070,100 1,284,120 1,605,150 2,140,200 3,210,300 and 6,420,600, with no remainder.
Since 6,420,600 cannot be divided by just 1 and 6,420,600, it is a composite number.