A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2003484 can be evenly divided by 1 2 3 4 6 7 12 14 17 21 23 28 34 42 46 51 61 68 69 84 92 102 119 122 138 161 183 204 238 244 276 322 357 366 391 427 476 483 644 714 732 782 854 966 1,037 1,173 1,281 1,403 1,428 1,564 1,708 1,932 2,074 2,346 2,562 2,737 2,806 3,111 4,148 4,209 4,692 5,124 5,474 5,612 6,222 7,259 8,211 8,418 9,821 10,948 12,444 14,518 16,422 16,836 19,642 21,777 23,851 29,036 29,463 32,844 39,284 43,554 47,702 58,926 71,553 87,108 95,404 117,852 143,106 166,957 286,212 333,914 500,871 667,828 1,001,742 and 2,003,484, with no remainder.
Since 2,003,484 cannot be divided by just 1 and 2,003,484, it is not a prime number.