A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8610600 can be evenly divided by 1 2 3 4 5 6 8 10 12 15 20 24 25 30 40 50 60 75 100 113 120 127 150 200 226 254 300 339 381 452 508 565 600 635 678 762 904 1,016 1,130 1,270 1,356 1,524 1,695 1,905 2,260 2,540 2,712 2,825 3,048 3,175 3,390 3,810 4,520 5,080 5,650 6,350 6,780 7,620 8,475 9,525 11,300 12,700 13,560 14,351 15,240 16,950 19,050 22,600 25,400 28,702 33,900 38,100 43,053 57,404 67,800 71,755 76,200 86,106 114,808 143,510 172,212 215,265 287,020 344,424 358,775 430,530 574,040 717,550 861,060 1,076,325 1,435,100 1,722,120 2,152,650 2,870,200 4,305,300 and 8,610,600, with no remainder.
Since 8,610,600 cannot be divided by just 1 and 8,610,600, it is not a prime number.