A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8723400 can be evenly divided by 1 2 3 4 5 6 7 8 10 12 14 15 20 21 24 25 28 30 31 35 40 42 50 56 60 62 67 70 75 84 93 100 105 120 124 134 140 150 155 168 175 186 200 201 210 217 248 268 280 300 310 335 350 372 402 420 434 465 469 525 536 600 620 651 670 700 744 775 804 840 868 930 938 1,005 1,050 1,085 1,240 1,302 1,340 1,400 1,407 1,550 1,608 1,675 1,736 1,860 1,876 2,010 2,077 2,100 2,170 2,325 2,345 2,604 2,680 2,814 3,100 3,255 3,350 3,720 3,752 4,020 4,154 4,200 4,340 4,650 4,690 5,025 5,208 5,425 5,628 6,200 6,231 6,510 6,700 7,035 8,040 8,308 8,680 9,300 9,380 10,050 10,385 10,850 11,256 11,725 12,462 13,020 13,400 14,070 14,539 16,275 16,616 18,600 18,760 20,100 20,770 21,700 23,450 24,924 26,040 28,140 29,078 31,155 32,550 35,175 40,200 41,540 43,400 43,617 46,900 49,848 51,925 56,280 58,156 62,310 65,100 70,350 72,695 83,080 87,234 93,800 103,850 116,312 124,620 130,200 140,700 145,390 155,775 174,468 207,700 218,085 249,240 281,400 290,780 311,550 348,936 363,475 415,400 436,170 581,560 623,100 726,950 872,340 1,090,425 1,246,200 1,453,900 1,744,680 2,180,850 2,907,800 4,361,700 and 8,723,400, with no remainder.
Since 8,723,400 cannot be divided by just 1 and 8,723,400, it is not a prime number.