A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2818650 can be evenly divided by 1 2 3 5 6 10 15 19 23 25 30 38 43 46 50 57 69 75 86 95 114 115 129 138 150 190 215 230 258 285 345 430 437 475 570 575 645 690 817 874 950 989 1,075 1,150 1,290 1,311 1,425 1,634 1,725 1,978 2,150 2,185 2,451 2,622 2,850 2,967 3,225 3,450 4,085 4,370 4,902 4,945 5,934 6,450 6,555 8,170 9,890 10,925 12,255 13,110 14,835 18,791 20,425 21,850 24,510 24,725 29,670 32,775 37,582 40,850 49,450 56,373 61,275 65,550 74,175 93,955 112,746 122,550 148,350 187,910 281,865 469,775 563,730 939,550 1,409,325 and 2,818,650, with no remainder.
Since 2,818,650 cannot be divided by just 1 and 2,818,650, it is not a prime number.