The number 3,857,700 can be evenly divided by 1 2 3 4 5 6 7 10 11 12 14 15 20 21 22 25 28 30 33 35 42 44 50 55 60 66 70 75 77 84 100 105 110 132 140 150 154 165 167 175 210 220 231 275 300 308 330 334 350 385 420 462 501 525 550 660 668 700 770 825 835 924 1,002 1,050 1,100 1,155 1,169 1,540 1,650 1,670 1,837 1,925 2,004 2,100 2,310 2,338 2,505 3,300 3,340 3,507 3,674 3,850 4,175 4,620 4,676 5,010 5,511 5,775 5,845 7,014 7,348 7,700 8,350 9,185 10,020 11,022 11,550 11,690 12,525 12,859 14,028 16,700 17,535 18,370 22,044 23,100 23,380 25,050 25,718 27,555 29,225 35,070 36,740 38,577 45,925 50,100 51,436 55,110 58,450 64,295 70,140 77,154 87,675 91,850 110,220 116,900 128,590 137,775 154,308 175,350 183,700 192,885 257,180 275,550 321,475 350,700 385,770 551,100 642,950 771,540 964,425 1,285,900 1,928,850 and 3,857,700, with no remainder.
Since 3,857,700 cannot be divided by just 1 and 3,857,700, it is a composite number.