A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1079364 can be evenly divided by 1 2 3 4 6 11 12 13 17 22 26 33 34 37 39 44 51 52 66 68 74 78 102 111 132 143 148 156 187 204 221 222 286 374 407 429 442 444 481 561 572 629 663 748 814 858 884 962 1,122 1,221 1,258 1,326 1,443 1,628 1,716 1,887 1,924 2,244 2,431 2,442 2,516 2,652 2,886 3,774 4,862 4,884 5,291 5,772 6,919 7,293 7,548 8,177 9,724 10,582 13,838 14,586 15,873 16,354 20,757 21,164 24,531 27,676 29,172 31,746 32,708 41,514 49,062 63,492 83,028 89,947 98,124 179,894 269,841 359,788 539,682 and 1,079,364, with no remainder.
Since 1,079,364 cannot be divided by just 1 and 1,079,364, it is not a prime number.