A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7931412 can be evenly divided by 1 2 3 4 6 9 12 18 23 27 31 36 46 54 62 69 92 93 103 108 124 138 186 206 207 276 279 309 372 412 414 558 618 621 713 828 837 927 1,116 1,236 1,242 1,426 1,674 1,854 2,139 2,369 2,484 2,781 2,852 3,193 3,348 3,708 4,278 4,738 5,562 6,386 6,417 7,107 8,556 9,476 9,579 11,124 12,772 12,834 14,214 19,158 19,251 21,321 25,668 28,428 28,737 38,316 38,502 42,642 57,474 63,963 73,439 77,004 85,284 86,211 114,948 127,926 146,878 172,422 220,317 255,852 293,756 344,844 440,634 660,951 881,268 1,321,902 1,982,853 2,643,804 3,965,706 and 7,931,412, with no remainder.
Since 7,931,412 cannot be divided by just 1 and 7,931,412, it is not a prime number.