A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2453880 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 13 15 20 22 24 26 30 33 39 40 44 52 55 60 65 66 78 88 104 110 120 121 130 132 143 156 165 169 195 220 242 260 264 286 312 330 338 363 390 429 440 484 507 520 572 605 660 676 715 726 780 845 858 968 1,014 1,144 1,210 1,320 1,352 1,430 1,452 1,560 1,573 1,690 1,716 1,815 1,859 2,028 2,145 2,420 2,535 2,860 2,904 3,146 3,380 3,432 3,630 3,718 4,056 4,290 4,719 4,840 5,070 5,577 5,720 6,292 6,760 7,260 7,436 7,865 8,580 9,295 9,438 10,140 11,154 12,584 14,520 14,872 15,730 17,160 18,590 18,876 20,280 20,449 22,308 23,595 27,885 31,460 37,180 37,752 40,898 44,616 47,190 55,770 61,347 62,920 74,360 81,796 94,380 102,245 111,540 122,694 163,592 188,760 204,490 223,080 245,388 306,735 408,980 490,776 613,470 817,960 1,226,940 and 2,453,880, with no remainder.
Since 2,453,880 cannot be divided by just 1 and 2,453,880, it is not a prime number.