The number 8,239,140 can be evenly divided by 1 2 3 4 5 6 7 9 10 12 13 14 15 18 20 21 26 28 30 35 36 39 42 45 52 60 63 65 70 78 84 90 91 105 117 126 130 140 156 180 182 195 210 234 252 260 273 315 364 390 420 455 468 503 546 585 630 780 819 910 1,006 1,092 1,170 1,260 1,365 1,509 1,638 1,820 2,012 2,340 2,515 2,730 3,018 3,276 3,521 4,095 4,527 5,030 5,460 6,036 6,539 7,042 7,545 8,190 9,054 10,060 10,563 13,078 14,084 15,090 16,380 17,605 18,108 19,617 21,126 22,635 26,156 30,180 31,689 32,695 35,210 39,234 42,252 45,270 45,773 52,815 58,851 63,378 65,390 70,420 78,468 90,540 91,546 98,085 105,630 117,702 126,756 130,780 137,319 158,445 183,092 196,170 211,260 228,865 235,404 274,638 294,255 316,890 392,340 411,957 457,730 549,276 588,510 633,780 686,595 823,914 915,460 1,177,020 1,373,190 1,647,828 2,059,785 2,746,380 4,119,570 and 8,239,140, with no remainder.
Since 8,239,140 cannot be divided by just 1 and 8,239,140, it is a composite number.