A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2534490 can be evenly divided by 1 2 3 5 6 7 9 10 14 15 18 21 27 30 35 42 45 54 63 70 81 90 105 126 135 149 162 189 210 243 270 298 315 378 405 447 486 567 630 745 810 894 945 1,043 1,134 1,215 1,341 1,490 1,701 1,890 2,086 2,235 2,430 2,682 2,835 3,129 3,402 4,023 4,470 5,215 5,670 6,258 6,705 8,046 8,505 9,387 10,430 12,069 13,410 15,645 17,010 18,774 20,115 24,138 28,161 31,290 36,207 40,230 46,935 56,322 60,345 72,414 84,483 93,870 120,690 140,805 168,966 181,035 253,449 281,610 362,070 422,415 506,898 844,830 1,267,245 and 2,534,490, with no remainder.
Since 2,534,490 cannot be divided by just 1 and 2,534,490, it is not a prime number.