A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7854000 can be evenly divided by 1 2 3 4 5 6 7 8 10 11 12 14 15 16 17 20 21 22 24 25 28 30 33 34 35 40 42 44 48 50 51 55 56 60 66 68 70 75 77 80 84 85 88 100 102 105 110 112 119 120 125 132 136 140 150 154 165 168 170 175 176 187 200 204 210 220 231 238 240 250 255 264 272 275 280 300 308 330 336 340 350 357 374 375 385 400 408 420 425 440 462 476 500 510 525 528 550 560 561 595 600 616 660 680 700 714 748 750 770 816 825 840 850 875 880 924 935 952 1,000 1,020 1,050 1,100 1,122 1,155 1,190 1,200 1,232 1,275 1,309 1,320 1,360 1,375 1,400 1,428 1,496 1,500 1,540 1,650 1,680 1,700 1,750 1,785 1,848 1,870 1,904 1,925 2,000 2,040 2,100 2,125 2,200 2,244 2,310 2,380 2,550 2,618 2,625 2,640 2,750 2,800 2,805 2,856 2,975 2,992 3,000 3,080 3,300 3,400 3,500 3,570 3,696 3,740 3,850 3,927 4,080 4,125 4,200 4,250 4,400 4,488 4,620 4,675 4,760 5,100 5,236 5,250 5,500 5,610 5,712 5,775 5,950 6,000 6,160 6,375 6,545 6,600 6,800 7,000 7,140 7,480 7,700 7,854 8,250 8,400 8,500 8,925 8,976 9,240 9,350 9,520 9,625 10,200 10,472 10,500 11,000 11,220 11,550 11,900 12,750 13,090 13,200 14,000 14,025 14,280 14,875 14,960 15,400 15,708 16,500 17,000 17,850 18,480 18,700 19,250 19,635 20,400 20,944 21,000 22,000 22,440 23,100 23,375 23,800 25,500 26,180 28,050 28,560 28,875 29,750 30,800 31,416 32,725 33,000 34,000 35,700 37,400 38,500 39,270 42,000 44,625 44,880 46,200 46,750 47,600 51,000 52,360 56,100 57,750 59,500 62,832 65,450 66,000 70,125 71,400 74,800 77,000 78,540 89,250 92,400 93,500 98,175 102,000 104,720 112,200 115,500 119,000 130,900 140,250 142,800 154,000 157,080 163,625 178,500 187,000 196,350 224,400 231,000 238,000 261,800 280,500 314,160 327,250 357,000 374,000 392,700 462,000 490,875 523,600 561,000 654,500 714,000 785,400 981,750 1,122,000 1,309,000 1,570,800 1,963,500 2,618,000 3,927,000 and 7,854,000, with no remainder.
Since 7,854,000 cannot be divided by just 1 and 7,854,000, it is not a prime number.