A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7984152 can be evenly divided by 1 2 3 4 6 8 9 11 12 17 18 22 24 33 34 36 44 51 66 68 72 88 99 102 132 136 153 187 198 204 264 306 374 396 408 561 593 612 748 792 1,122 1,186 1,224 1,496 1,683 1,779 2,244 2,372 3,366 3,558 4,488 4,744 5,337 6,523 6,732 7,116 10,081 10,674 13,046 13,464 14,232 19,569 20,162 21,348 26,092 30,243 39,138 40,324 42,696 52,184 58,707 60,486 78,276 80,648 90,729 110,891 117,414 120,972 156,552 181,458 221,782 234,828 241,944 332,673 362,916 443,564 469,656 665,346 725,832 887,128 998,019 1,330,692 1,996,038 2,661,384 3,992,076 and 7,984,152, with no remainder.
Since 7,984,152 cannot be divided by just 1 and 7,984,152, it is not a prime number.