A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3713710 can be evenly divided by 1 2 5 7 10 11 13 14 22 26 35 49 53 55 65 70 77 91 98 106 110 130 143 154 182 245 265 286 371 385 455 490 530 539 583 637 689 715 742 770 910 1,001 1,078 1,166 1,274 1,378 1,430 1,855 2,002 2,597 2,695 2,915 3,185 3,445 3,710 4,081 4,823 5,005 5,194 5,390 5,830 6,370 6,890 7,007 7,579 8,162 9,646 10,010 12,985 14,014 15,158 20,405 24,115 25,970 28,567 33,761 35,035 37,895 40,810 48,230 53,053 57,134 67,522 70,070 75,790 106,106 142,835 168,805 265,265 285,670 337,610 371,371 530,530 742,742 1,856,855 and 3,713,710, with no remainder.
Since 3,713,710 cannot be divided by just 1 and 3,713,710, it is not a prime number.