A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7523880 can be evenly divided by 1 2 3 4 5 6 7 8 10 12 13 14 15 20 21 24 26 28 30 35 39 40 42 52 53 56 60 65 70 78 84 91 104 105 106 120 130 140 156 159 168 169 182 195 210 212 260 265 273 280 312 318 338 364 371 390 420 424 455 507 520 530 546 636 676 689 728 742 780 795 840 845 910 1,014 1,060 1,092 1,113 1,183 1,272 1,352 1,365 1,378 1,484 1,560 1,590 1,690 1,820 1,855 2,028 2,067 2,120 2,184 2,226 2,366 2,535 2,730 2,756 2,968 3,180 3,380 3,445 3,549 3,640 3,710 4,056 4,134 4,452 4,732 4,823 5,070 5,460 5,512 5,565 5,915 6,360 6,760 6,890 7,098 7,420 8,268 8,904 8,957 9,464 9,646 10,140 10,335 10,920 11,130 11,830 13,780 14,196 14,469 14,840 16,536 17,745 17,914 19,292 20,280 20,670 22,260 23,660 24,115 26,871 27,560 28,392 28,938 35,490 35,828 38,584 41,340 44,520 44,785 47,320 48,230 53,742 57,876 62,699 70,980 71,656 72,345 82,680 89,570 96,460 107,484 115,752 125,398 134,355 141,960 144,690 179,140 188,097 192,920 214,968 250,796 268,710 289,380 313,495 358,280 376,194 501,592 537,420 578,760 626,990 752,388 940,485 1,074,840 1,253,980 1,504,776 1,880,970 2,507,960 3,761,940 and 7,523,880, with no remainder.
Since 7,523,880 cannot be divided by just 1 and 7,523,880, it is not a prime number.