A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2311400 can be evenly divided by 1 2 4 5 7 8 10 13 14 20 25 26 28 35 40 50 52 56 65 70 91 100 104 127 130 140 175 182 200 254 260 280 325 350 364 455 508 520 635 650 700 728 889 910 1,016 1,270 1,300 1,400 1,651 1,778 1,820 2,275 2,540 2,600 3,175 3,302 3,556 3,640 4,445 4,550 5,080 6,350 6,604 7,112 8,255 8,890 9,100 11,557 12,700 13,208 16,510 17,780 18,200 22,225 23,114 25,400 33,020 35,560 41,275 44,450 46,228 57,785 66,040 82,550 88,900 92,456 115,570 165,100 177,800 231,140 288,925 330,200 462,280 577,850 1,155,700 and 2,311,400, with no remainder.
Since 2,311,400 cannot be divided by just 1 and 2,311,400, it is not a prime number.