The number 4,089,540 can be evenly divided by 1 2 3 4 5 6 7 10 12 13 14 15 20 21 26 28 30 35 39 42 49 52 60 65 70 78 84 91 98 105 107 130 140 147 156 182 195 196 210 214 245 260 273 294 321 364 390 420 428 455 490 535 546 588 637 642 735 749 780 910 980 1,070 1,092 1,274 1,284 1,365 1,391 1,470 1,498 1,605 1,820 1,911 2,140 2,247 2,548 2,730 2,782 2,940 2,996 3,185 3,210 3,745 3,822 4,173 4,494 5,243 5,460 5,564 6,370 6,420 6,955 7,490 7,644 8,346 8,988 9,555 9,737 10,486 11,235 12,740 13,910 14,980 15,729 16,692 19,110 19,474 20,865 20,972 22,470 26,215 27,820 29,211 31,458 38,220 38,948 41,730 44,940 48,685 52,430 58,422 62,916 68,159 78,645 83,460 97,370 104,860 116,844 136,318 146,055 157,290 194,740 204,477 272,636 292,110 314,580 340,795 408,954 584,220 681,590 817,908 1,022,385 1,363,180 2,044,770 and 4,089,540, with no remainder.
Since 4,089,540 cannot be divided by just 1 and 4,089,540, it is a composite number.