The number 3,888,900 can be evenly divided by 1 2 3 4 5 6 9 10 12 15 18 20 25 29 30 36 45 50 58 60 75 87 90 100 116 145 149 150 174 180 225 261 290 298 300 348 435 447 450 522 580 596 725 745 870 894 900 1,044 1,305 1,341 1,450 1,490 1,740 1,788 2,175 2,235 2,610 2,682 2,900 2,980 3,725 4,321 4,350 4,470 5,220 5,364 6,525 6,705 7,450 8,642 8,700 8,940 11,175 12,963 13,050 13,410 14,900 17,284 21,605 22,350 25,926 26,100 26,820 33,525 38,889 43,210 44,700 51,852 64,815 67,050 77,778 86,420 108,025 129,630 134,100 155,556 194,445 216,050 259,260 324,075 388,890 432,100 648,150 777,780 972,225 1,296,300 1,944,450 and 3,888,900, with no remainder.
Since 3,888,900 cannot be divided by just 1 and 3,888,900, it is a composite number.