A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2122260 can be evenly divided by 1 2 3 4 5 6 7 10 12 14 15 20 21 28 30 31 35 42 60 62 70 84 93 105 124 140 155 163 186 210 217 310 326 372 420 434 465 489 620 651 652 815 868 930 978 1,085 1,141 1,302 1,630 1,860 1,956 2,170 2,282 2,445 2,604 3,255 3,260 3,423 4,340 4,564 4,890 5,053 5,705 6,510 6,846 9,780 10,106 11,410 13,020 13,692 15,159 17,115 20,212 22,820 25,265 30,318 34,230 35,371 50,530 60,636 68,460 70,742 75,795 101,060 106,113 141,484 151,590 176,855 212,226 303,180 353,710 424,452 530,565 707,420 1,061,130 and 2,122,260, with no remainder.
Since 2,122,260 cannot be divided by just 1 and 2,122,260, it is not a prime number.