A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2121350 can be evenly divided by 1 2 5 7 10 11 14 19 22 25 29 35 38 50 55 58 70 77 95 110 133 145 154 175 190 203 209 266 275 290 319 350 385 406 418 475 550 551 638 665 725 770 950 1,015 1,045 1,102 1,330 1,450 1,463 1,595 1,925 2,030 2,090 2,233 2,755 2,926 3,190 3,325 3,850 3,857 4,466 5,075 5,225 5,510 6,061 6,650 7,315 7,714 7,975 10,150 10,450 11,165 12,122 13,775 14,630 15,950 19,285 22,330 27,550 30,305 36,575 38,570 42,427 55,825 60,610 73,150 84,854 96,425 111,650 151,525 192,850 212,135 303,050 424,270 1,060,675 and 2,121,350, with no remainder.
Since 2,121,350 cannot be divided by just 1 and 2,121,350, it is not a prime number.