A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4005540 can be evenly divided by 1 2 3 4 5 6 7 9 10 11 12 14 15 17 18 20 21 22 28 30 33 34 35 36 42 44 45 51 55 60 63 66 68 70 77 84 85 90 99 102 105 110 119 126 132 140 153 154 165 170 180 187 198 204 210 220 231 238 252 255 289 306 308 315 330 340 357 374 385 396 420 462 476 495 510 561 578 595 612 630 660 693 714 748 765 770 867 924 935 990 1,020 1,071 1,122 1,155 1,156 1,190 1,260 1,309 1,386 1,428 1,445 1,530 1,540 1,683 1,734 1,785 1,870 1,980 2,023 2,142 2,244 2,310 2,380 2,601 2,618 2,772 2,805 2,890 3,060 3,179 3,366 3,465 3,468 3,570 3,740 3,927 4,046 4,284 4,335 4,620 5,202 5,236 5,355 5,610 5,780 6,069 6,358 6,545 6,732 6,930 7,140 7,854 8,092 8,415 8,670 9,537 10,115 10,404 10,710 11,220 11,781 12,138 12,716 13,005 13,090 13,860 15,708 15,895 16,830 17,340 18,207 19,074 19,635 20,230 21,420 22,253 23,562 24,276 26,010 26,180 28,611 30,345 31,790 33,660 36,414 38,148 39,270 40,460 44,506 47,124 47,685 52,020 57,222 58,905 60,690 63,580 66,759 72,828 78,540 89,012 91,035 95,370 111,265 114,444 117,810 121,380 133,518 143,055 182,070 190,740 200,277 222,530 235,620 267,036 286,110 333,795 364,140 400,554 445,060 572,220 667,590 801,108 1,001,385 1,335,180 2,002,770 and 4,005,540, with no remainder.
Since 4,005,540 cannot be divided by just 1 and 4,005,540, it is not a prime number.