A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4047615 can be evenly divided by 1 3 5 9 11 13 15 17 33 37 39 45 51 55 65 85 99 111 117 143 153 165 185 187 195 221 255 333 407 429 481 495 555 561 585 629 663 715 765 935 1,105 1,221 1,287 1,443 1,665 1,683 1,887 1,989 2,035 2,145 2,405 2,431 2,805 3,145 3,315 3,663 4,329 5,291 5,661 6,105 6,435 6,919 7,215 7,293 8,177 8,415 9,435 9,945 12,155 15,873 18,315 20,757 21,645 21,879 24,531 26,455 28,305 34,595 36,465 40,885 47,619 62,271 73,593 79,365 89,947 103,785 109,395 122,655 238,095 269,841 311,355 367,965 449,735 809,523 1,349,205 and 4,047,615, with no remainder.
Since 4,047,615 cannot be divided by just 1 and 4,047,615, it is not a prime number.