A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2587200 can be evenly divided by 1 2 3 4 5 6 7 8 10 11 12 14 15 16 20 21 22 24 25 28 30 32 33 35 40 42 44 48 49 50 55 56 60 64 66 70 75 77 80 84 88 96 98 100 105 110 112 120 132 140 147 150 154 160 165 168 175 176 192 196 200 210 220 224 231 240 245 264 275 280 294 300 308 320 330 336 350 352 385 392 400 420 440 448 462 480 490 525 528 539 550 560 588 600 616 660 672 700 704 735 770 784 800 825 840 880 924 960 980 1,050 1,056 1,078 1,100 1,120 1,155 1,176 1,200 1,225 1,232 1,320 1,344 1,400 1,470 1,540 1,568 1,600 1,617 1,650 1,680 1,760 1,848 1,925 1,960 2,100 2,112 2,156 2,200 2,240 2,310 2,352 2,400 2,450 2,464 2,640 2,695 2,800 2,940 3,080 3,136 3,234 3,300 3,360 3,520 3,675 3,696 3,850 3,920 4,200 4,312 4,400 4,620 4,704 4,800 4,900 4,928 5,280 5,390 5,600 5,775 5,880 6,160 6,468 6,600 6,720 7,350 7,392 7,700 7,840 8,085 8,400 8,624 8,800 9,240 9,408 9,800 10,560 10,780 11,200 11,550 11,760 12,320 12,936 13,200 13,475 14,700 14,784 15,400 15,680 16,170 16,800 17,248 17,600 18,480 19,600 21,560 23,100 23,520 24,640 25,872 26,400 26,950 29,400 30,800 32,340 33,600 34,496 36,960 39,200 40,425 43,120 46,200 47,040 51,744 52,800 53,900 58,800 61,600 64,680 73,920 78,400 80,850 86,240 92,400 103,488 107,800 117,600 123,200 129,360 161,700 172,480 184,800 215,600 235,200 258,720 323,400 369,600 431,200 517,440 646,800 862,400 1,293,600 and 2,587,200, with no remainder.
Since 2,587,200 cannot be divided by just 1 and 2,587,200, it is not a prime number.