A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8316756 can be evenly divided by 1 2 3 4 6 7 9 12 14 18 19 21 27 28 36 38 42 54 57 63 76 81 84 108 114 126 133 162 171 189 193 228 252 266 324 342 378 386 399 513 532 567 579 684 756 772 798 1,026 1,134 1,158 1,197 1,351 1,539 1,596 1,737 2,052 2,268 2,316 2,394 2,702 3,078 3,474 3,591 3,667 4,053 4,788 5,211 5,404 6,156 6,948 7,182 7,334 8,106 10,422 10,773 11,001 12,159 14,364 14,668 15,633 16,212 20,844 21,546 22,002 24,318 25,669 31,266 33,003 36,477 43,092 44,004 48,636 51,338 62,532 66,006 72,954 77,007 99,009 102,676 109,431 132,012 145,908 154,014 198,018 218,862 231,021 297,027 308,028 396,036 437,724 462,042 594,054 693,063 924,084 1,188,108 1,386,126 2,079,189 2,772,252 4,158,378 and 8,316,756, with no remainder.
Since 8,316,756 cannot be divided by just 1 and 8,316,756, it is not a prime number.