A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7583964 can be evenly divided by 1 2 3 4 6 12 19 29 31 37 38 57 58 62 74 76 87 93 111 114 116 124 148 174 186 222 228 348 372 444 551 589 703 899 1,073 1,102 1,147 1,178 1,406 1,653 1,767 1,798 2,109 2,146 2,204 2,294 2,356 2,697 2,812 3,219 3,306 3,441 3,534 3,596 4,218 4,292 4,588 5,394 6,438 6,612 6,882 7,068 8,436 10,788 12,876 13,764 17,081 20,387 21,793 33,263 34,162 40,774 43,586 51,243 61,161 65,379 66,526 68,324 81,548 87,172 99,789 102,486 122,322 130,758 133,052 199,578 204,972 244,644 261,516 399,156 631,997 1,263,994 1,895,991 2,527,988 3,791,982 and 7,583,964, with no remainder.
Since 7,583,964 cannot be divided by just 1 and 7,583,964, it is not a prime number.