A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7579656 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 18 21 24 27 28 36 42 54 56 63 72 81 84 108 126 162 168 189 216 243 252 324 378 486 504 557 567 648 756 972 1,114 1,134 1,512 1,671 1,701 1,944 2,228 2,268 3,342 3,402 3,899 4,456 4,536 5,013 6,684 6,804 7,798 10,026 11,697 13,368 13,608 15,039 15,596 20,052 23,394 30,078 31,192 35,091 40,104 45,117 46,788 60,156 70,182 90,234 93,576 105,273 120,312 135,351 140,364 180,468 210,546 270,702 280,728 315,819 360,936 421,092 541,404 631,638 842,184 947,457 1,082,808 1,263,276 1,894,914 2,526,552 3,789,828 and 7,579,656, with no remainder.
Since 7,579,656 cannot be divided by just 1 and 7,579,656, it is not a prime number.