A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2114840 can be evenly divided by 1 2 4 5 7 8 10 13 14 20 26 28 35 40 49 52 56 65 70 83 91 98 104 130 140 166 182 196 245 260 280 332 364 392 415 455 490 520 581 637 664 728 830 910 980 1,079 1,162 1,274 1,660 1,820 1,960 2,158 2,324 2,548 2,905 3,185 3,320 3,640 4,067 4,316 4,648 5,096 5,395 5,810 6,370 7,553 8,134 8,632 10,790 11,620 12,740 15,106 16,268 20,335 21,580 23,240 25,480 30,212 32,536 37,765 40,670 43,160 52,871 60,424 75,530 81,340 105,742 151,060 162,680 211,484 264,355 302,120 422,968 528,710 1,057,420 and 2,114,840, with no remainder.
Since 2,114,840 cannot be divided by just 1 and 2,114,840, it is not a prime number.