A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3939012 can be evenly divided by 1 2 3 4 6 7 9 11 12 14 18 21 22 28 29 33 36 42 44 49 58 63 66 77 84 87 98 99 116 126 132 147 154 174 196 198 203 231 252 261 294 308 319 343 348 396 406 441 462 522 539 588 609 638 686 693 812 882 924 957 1,029 1,044 1,078 1,218 1,276 1,372 1,386 1,421 1,617 1,764 1,827 1,914 2,058 2,156 2,233 2,436 2,772 2,842 2,871 3,087 3,234 3,654 3,773 3,828 4,116 4,263 4,466 4,851 5,684 5,742 6,174 6,468 6,699 7,308 7,546 8,526 8,932 9,702 9,947 11,319 11,484 12,348 12,789 13,398 15,092 15,631 17,052 19,404 19,894 20,097 22,638 25,578 26,796 29,841 31,262 33,957 39,788 40,194 45,276 46,893 51,156 59,682 62,524 67,914 80,388 89,523 93,786 109,417 119,364 135,828 140,679 179,046 187,572 218,834 281,358 328,251 358,092 437,668 562,716 656,502 984,753 1,313,004 1,969,506 and 3,939,012, with no remainder.
Since 3,939,012 cannot be divided by just 1 and 3,939,012, it is not a prime number.