A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1804110 can be evenly divided by 1 2 3 5 6 7 10 11 14 15 21 22 30 33 35 42 55 66 70 71 77 105 110 121 142 154 165 210 213 231 242 330 355 363 385 426 462 497 605 710 726 770 781 847 994 1,065 1,155 1,210 1,491 1,562 1,694 1,815 2,130 2,310 2,343 2,485 2,541 2,982 3,630 3,905 4,235 4,686 4,970 5,082 5,467 7,455 7,810 8,470 8,591 10,934 11,715 12,705 14,910 16,401 17,182 23,430 25,410 25,773 27,335 32,802 42,955 51,546 54,670 60,137 82,005 85,910 120,274 128,865 164,010 180,411 257,730 300,685 360,822 601,370 902,055 and 1,804,110, with no remainder.
Since 1,804,110 cannot be divided by just 1 and 1,804,110, it is not a prime number.