A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8296596 can be evenly divided by 1 2 3 4 6 7 9 11 12 14 18 21 22 28 33 36 41 42 44 63 66 73 77 82 84 99 123 126 132 146 154 164 198 219 231 246 252 287 292 308 369 396 438 451 462 492 511 574 657 693 738 803 861 876 902 924 1,022 1,148 1,314 1,353 1,386 1,476 1,533 1,606 1,722 1,804 2,044 2,409 2,583 2,628 2,706 2,772 2,993 3,066 3,157 3,212 3,444 4,059 4,599 4,818 5,166 5,412 5,621 5,986 6,132 6,314 7,227 8,118 8,979 9,198 9,471 9,636 10,332 11,242 11,972 12,628 14,454 16,236 16,863 17,958 18,396 18,942 20,951 22,484 26,937 28,413 28,908 32,923 33,726 35,916 37,884 41,902 50,589 53,874 56,826 62,853 65,846 67,452 83,804 98,769 101,178 107,748 113,652 125,706 131,692 188,559 197,538 202,356 230,461 251,412 296,307 377,118 395,076 460,922 592,614 691,383 754,236 921,844 1,185,228 1,382,766 2,074,149 2,765,532 4,148,298 and 8,296,596, with no remainder.
Since 8,296,596 cannot be divided by just 1 and 8,296,596, it is not a prime number.