A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2306850 can be evenly divided by 1 2 3 5 6 7 10 13 14 15 21 25 26 30 35 39 42 50 65 70 75 78 91 105 130 150 169 175 182 195 210 273 325 338 350 390 455 507 525 546 650 845 910 975 1,014 1,050 1,183 1,365 1,690 1,950 2,197 2,275 2,366 2,535 2,730 3,549 4,225 4,394 4,550 5,070 5,915 6,591 6,825 7,098 8,450 10,985 11,830 12,675 13,182 13,650 15,379 17,745 21,970 25,350 29,575 30,758 32,955 35,490 46,137 54,925 59,150 65,910 76,895 88,725 92,274 109,850 153,790 164,775 177,450 230,685 329,550 384,475 461,370 768,950 1,153,425 and 2,306,850, with no remainder.
Since 2,306,850 cannot be divided by just 1 and 2,306,850, it is not a prime number.