The number 3,691,380 can be evenly divided by 1 2 3 4 5 6 7 10 11 12 14 15 17 20 21 22 28 30 33 34 35 42 44 47 51 55 60 66 68 70 77 84 85 94 102 105 110 119 132 140 141 154 165 170 187 188 204 210 220 231 235 238 255 282 308 329 330 340 357 374 385 420 462 470 476 510 517 561 564 595 658 660 705 714 748 770 799 924 935 940 987 1,020 1,034 1,122 1,155 1,190 1,309 1,316 1,410 1,428 1,540 1,551 1,598 1,645 1,785 1,870 1,974 2,068 2,244 2,310 2,380 2,397 2,585 2,618 2,805 2,820 3,102 3,196 3,290 3,570 3,619 3,740 3,927 3,948 3,995 4,620 4,794 4,935 5,170 5,236 5,593 5,610 6,204 6,545 6,580 7,140 7,238 7,755 7,854 7,990 8,789 9,588 9,870 10,340 10,857 11,186 11,220 11,985 13,090 14,476 15,510 15,708 15,980 16,779 17,578 18,095 19,635 19,740 21,714 22,372 23,970 26,180 26,367 27,965 31,020 33,558 35,156 36,190 39,270 43,428 43,945 47,940 52,734 54,285 55,930 61,523 67,116 72,380 78,540 83,895 87,890 105,468 108,570 111,860 123,046 131,835 167,790 175,780 184,569 217,140 246,092 263,670 307,615 335,580 369,138 527,340 615,230 738,276 922,845 1,230,460 1,845,690 and 3,691,380, with no remainder.
Since 3,691,380 cannot be divided by just 1 and 3,691,380, it is a composite number.