A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3754020 can be evenly divided by 1 2 3 4 5 6 10 12 15 19 20 30 37 38 57 60 74 76 89 95 111 114 148 178 185 190 222 228 267 285 356 370 380 444 445 534 555 570 703 740 890 1,068 1,110 1,140 1,335 1,406 1,691 1,780 2,109 2,220 2,670 2,812 3,293 3,382 3,515 4,218 5,073 5,340 6,586 6,764 7,030 8,436 8,455 9,879 10,146 10,545 13,172 14,060 16,465 16,910 19,758 20,292 21,090 25,365 32,930 33,820 39,516 42,180 49,395 50,730 62,567 65,860 98,790 101,460 125,134 187,701 197,580 250,268 312,835 375,402 625,670 750,804 938,505 1,251,340 1,877,010 and 3,754,020, with no remainder.
Since 3,754,020 cannot be divided by just 1 and 3,754,020, it is not a prime number.