The number 1,385,670 can be evenly divided by 1 2 3 5 6 10 11 13 15 17 19 22 26 30 33 34 38 39 51 55 57 65 66 78 85 95 102 110 114 130 143 165 170 187 190 195 209 221 247 255 285 286 323 330 374 390 418 429 442 494 510 561 570 627 646 663 715 741 858 935 969 1,045 1,105 1,122 1,235 1,254 1,326 1,430 1,482 1,615 1,870 1,938 2,090 2,145 2,210 2,431 2,470 2,717 2,805 3,135 3,230 3,315 3,553 3,705 4,199 4,290 4,845 4,862 5,434 5,610 6,270 6,630 7,106 7,293 7,410 8,151 8,398 9,690 10,659 12,155 12,597 13,585 14,586 16,302 17,765 20,995 21,318 24,310 25,194 27,170 35,530 36,465 40,755 41,990 46,189 53,295 62,985 72,930 81,510 92,378 106,590 125,970 138,567 230,945 277,134 461,890 692,835 and 1,385,670, with no remainder.
Since 1,385,670 cannot be divided by just 1 and 1,385,670, it is a composite number.