A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1669800 can be evenly divided by 1 2 3 4 5 6 8 10 11 12 15 20 22 23 24 25 30 33 40 44 46 50 55 60 66 69 75 88 92 100 110 115 120 121 132 138 150 165 184 200 220 230 242 253 264 275 276 300 330 345 363 440 460 484 506 550 552 575 600 605 660 690 726 759 825 920 968 1,012 1,100 1,150 1,210 1,265 1,320 1,380 1,452 1,518 1,650 1,725 1,815 2,024 2,200 2,300 2,420 2,530 2,760 2,783 2,904 3,025 3,036 3,300 3,450 3,630 3,795 4,600 4,840 5,060 5,566 6,050 6,072 6,325 6,600 6,900 7,260 7,590 8,349 9,075 10,120 11,132 12,100 12,650 13,800 13,915 14,520 15,180 16,698 18,150 18,975 22,264 24,200 25,300 27,830 30,360 33,396 36,300 37,950 41,745 50,600 55,660 66,792 69,575 72,600 75,900 83,490 111,320 139,150 151,800 166,980 208,725 278,300 333,960 417,450 556,600 834,900 and 1,669,800, with no remainder.
Since 1,669,800 cannot be divided by just 1 and 1,669,800, it is not a prime number.