A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5665680 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 27 30 36 40 43 45 48 54 60 61 72 80 86 90 108 120 122 129 135 144 172 180 183 215 216 240 244 258 270 305 344 360 366 387 430 432 488 516 540 549 610 645 688 720 732 774 860 915 976 1,032 1,080 1,098 1,161 1,220 1,290 1,464 1,548 1,647 1,720 1,830 1,935 2,064 2,160 2,196 2,322 2,440 2,580 2,623 2,745 2,928 3,096 3,294 3,440 3,660 3,870 4,392 4,644 4,880 5,160 5,246 5,490 5,805 6,192 6,588 7,320 7,740 7,869 8,235 8,784 9,288 10,320 10,492 10,980 11,610 13,115 13,176 14,640 15,480 15,738 16,470 18,576 20,984 21,960 23,220 23,607 26,230 26,352 30,960 31,476 32,940 39,345 41,968 43,920 46,440 47,214 52,460 62,952 65,880 70,821 78,690 92,880 94,428 104,920 118,035 125,904 131,760 141,642 157,380 188,856 209,840 236,070 283,284 314,760 354,105 377,712 472,140 566,568 629,520 708,210 944,280 1,133,136 1,416,420 1,888,560 2,832,840 and 5,665,680, with no remainder.
Since 5,665,680 cannot be divided by just 1 and 5,665,680, it is not a prime number.