A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4361280 can be evenly divided by 1 2 3 4 5 6 7 8 10 11 12 14 15 16 20 21 22 24 28 30 32 33 35 40 42 44 48 55 56 59 60 64 66 70 77 80 84 88 96 105 110 112 118 120 132 140 154 160 165 168 176 177 192 210 220 224 231 236 240 264 280 295 308 320 330 336 352 354 385 413 420 440 448 462 472 480 528 560 590 616 649 660 672 704 708 770 826 840 880 885 924 944 960 1,056 1,120 1,155 1,180 1,232 1,239 1,298 1,320 1,344 1,416 1,540 1,652 1,680 1,760 1,770 1,848 1,888 1,947 2,065 2,112 2,240 2,310 2,360 2,464 2,478 2,596 2,640 2,832 3,080 3,245 3,304 3,360 3,520 3,540 3,696 3,776 3,894 4,130 4,543 4,620 4,720 4,928 4,956 5,192 5,280 5,664 6,160 6,195 6,490 6,608 6,720 7,080 7,392 7,788 8,260 9,086 9,240 9,440 9,735 9,912 10,384 10,560 11,328 12,320 12,390 12,980 13,216 13,629 14,160 14,784 15,576 16,520 18,172 18,480 18,880 19,470 19,824 20,768 22,715 24,640 24,780 25,960 26,432 27,258 28,320 31,152 33,040 36,344 36,960 38,940 39,648 41,536 45,430 49,560 51,920 54,516 56,640 62,304 66,080 68,145 72,688 73,920 77,880 79,296 90,860 99,120 103,840 109,032 124,608 132,160 136,290 145,376 155,760 181,720 198,240 207,680 218,064 272,580 290,752 311,520 363,440 396,480 436,128 545,160 623,040 726,880 872,256 1,090,320 1,453,760 2,180,640 and 4,361,280, with no remainder.
Since 4,361,280 cannot be divided by just 1 and 4,361,280, it is not a prime number.