A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8619600 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 15 16 20 22 24 25 30 33 40 44 48 50 55 60 66 75 80 88 100 110 120 132 150 165 176 200 220 240 264 275 300 330 400 440 528 550 600 653 660 825 880 1,100 1,200 1,306 1,320 1,650 1,959 2,200 2,612 2,640 3,265 3,300 3,918 4,400 5,224 6,530 6,600 7,183 7,836 9,795 10,448 13,060 13,200 14,366 15,672 16,325 19,590 21,549 26,120 28,732 31,344 32,650 35,915 39,180 43,098 48,975 52,240 57,464 65,300 71,830 78,360 86,196 97,950 107,745 114,928 130,600 143,660 156,720 172,392 179,575 195,900 215,490 261,200 287,320 344,784 359,150 391,800 430,980 538,725 574,640 718,300 783,600 861,960 1,077,450 1,436,600 1,723,920 2,154,900 2,873,200 4,309,800 and 8,619,600, with no remainder.
Since 8,619,600 cannot be divided by just 1 and 8,619,600, it is not a prime number.