A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6142620 can be evenly divided by 1 2 3 4 5 6 10 11 12 15 20 22 30 33 41 44 55 60 66 82 110 123 132 164 165 205 220 227 246 330 410 451 454 492 615 660 681 820 902 908 1,135 1,230 1,353 1,362 1,804 2,255 2,270 2,460 2,497 2,706 2,724 3,405 4,510 4,540 4,994 5,412 6,765 6,810 7,491 9,020 9,307 9,988 12,485 13,530 13,620 14,982 18,614 24,970 27,060 27,921 29,964 37,228 37,455 46,535 49,940 55,842 74,910 93,070 102,377 111,684 139,605 149,820 186,140 204,754 279,210 307,131 409,508 511,885 558,420 614,262 1,023,770 1,228,524 1,535,655 2,047,540 3,071,310 and 6,142,620, with no remainder.
Since 6,142,620 cannot be divided by just 1 and 6,142,620, it is not a prime number.