The number 3,586,440 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 13 15 19 20 22 24 26 30 33 38 39 40 44 52 55 57 60 65 66 76 78 88 95 104 110 114 120 121 130 132 143 152 156 165 190 195 209 220 228 242 247 260 264 285 286 312 330 363 380 390 418 429 440 456 484 494 520 570 572 605 627 660 715 726 741 760 780 836 858 968 988 1,045 1,140 1,144 1,210 1,235 1,254 1,320 1,430 1,452 1,482 1,560 1,573 1,672 1,716 1,815 1,976 2,090 2,145 2,280 2,299 2,420 2,470 2,508 2,717 2,860 2,904 2,964 3,135 3,146 3,432 3,630 3,705 4,180 4,290 4,598 4,719 4,840 4,940 5,016 5,434 5,720 5,928 6,270 6,292 6,897 7,260 7,410 7,865 8,151 8,360 8,580 9,196 9,438 9,880 10,868 11,495 12,540 12,584 13,585 13,794 14,520 14,820 15,730 16,302 17,160 18,392 18,876 21,736 22,990 23,595 25,080 27,170 27,588 29,640 29,887 31,460 32,604 34,485 37,752 40,755 45,980 47,190 54,340 55,176 59,774 62,920 65,208 68,970 81,510 89,661 91,960 94,380 108,680 119,548 137,940 149,435 163,020 179,322 188,760 239,096 275,880 298,870 326,040 358,644 448,305 597,740 717,288 896,610 1,195,480 1,793,220 and 3,586,440, with no remainder.
Since 3,586,440 cannot be divided by just 1 and 3,586,440, it is a composite number.