A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2285556 can be evenly divided by 1 2 3 4 6 7 12 13 14 21 23 26 28 39 42 46 49 52 69 78 84 91 92 98 138 147 156 161 169 182 196 273 276 294 299 322 338 364 483 507 546 588 598 637 644 676 897 966 1,014 1,092 1,127 1,183 1,196 1,274 1,794 1,911 1,932 2,028 2,093 2,254 2,366 2,548 3,381 3,549 3,588 3,822 3,887 4,186 4,508 4,732 6,279 6,762 7,098 7,644 7,774 8,281 8,372 11,661 12,558 13,524 14,196 14,651 15,548 16,562 23,322 24,843 25,116 27,209 29,302 33,124 43,953 46,644 49,686 54,418 58,604 81,627 87,906 99,372 108,836 163,254 175,812 190,463 326,508 380,926 571,389 761,852 1,142,778 and 2,285,556, with no remainder.
Since 2,285,556 cannot be divided by just 1 and 2,285,556, it is not a prime number.