A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5424120 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 13 15 18 19 20 24 26 30 36 38 39 40 45 52 57 60 61 65 72 76 78 90 95 104 114 117 120 122 130 152 156 171 180 183 190 195 228 234 244 247 260 285 305 312 342 360 366 380 390 456 468 488 494 520 549 570 585 610 684 732 741 760 780 793 855 915 936 988 1,098 1,140 1,159 1,170 1,220 1,235 1,368 1,464 1,482 1,560 1,586 1,710 1,830 1,976 2,196 2,223 2,280 2,318 2,340 2,379 2,440 2,470 2,745 2,964 3,172 3,420 3,477 3,660 3,705 3,965 4,392 4,446 4,636 4,680 4,758 4,940 5,490 5,795 5,928 6,344 6,840 6,954 7,137 7,320 7,410 7,930 8,892 9,272 9,516 9,880 10,431 10,980 11,115 11,590 11,895 13,908 14,274 14,820 15,067 15,860 17,385 17,784 19,032 20,862 21,960 22,230 23,180 23,790 27,816 28,548 29,640 30,134 31,720 34,770 35,685 41,724 44,460 45,201 46,360 47,580 52,155 57,096 60,268 69,540 71,370 75,335 83,448 88,920 90,402 95,160 104,310 120,536 135,603 139,080 142,740 150,670 180,804 208,620 226,005 271,206 285,480 301,340 361,608 417,240 452,010 542,412 602,680 678,015 904,020 1,084,824 1,356,030 1,808,040 2,712,060 and 5,424,120, with no remainder.
Since 5,424,120 cannot be divided by just 1 and 5,424,120, it is not a prime number.