A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1963500 can be evenly divided by 1 2 3 4 5 6 7 10 11 12 14 15 17 20 21 22 25 28 30 33 34 35 42 44 50 51 55 60 66 68 70 75 77 84 85 100 102 105 110 119 125 132 140 150 154 165 170 175 187 204 210 220 231 238 250 255 275 300 308 330 340 350 357 374 375 385 420 425 462 476 500 510 525 550 561 595 660 700 714 748 750 770 825 850 875 924 935 1,020 1,050 1,100 1,122 1,155 1,190 1,275 1,309 1,375 1,428 1,500 1,540 1,650 1,700 1,750 1,785 1,870 1,925 2,100 2,125 2,244 2,310 2,380 2,550 2,618 2,625 2,750 2,805 2,975 3,300 3,500 3,570 3,740 3,850 3,927 4,125 4,250 4,620 4,675 5,100 5,236 5,250 5,500 5,610 5,775 5,950 6,375 6,545 7,140 7,700 7,854 8,250 8,500 8,925 9,350 9,625 10,500 11,220 11,550 11,900 12,750 13,090 14,025 14,875 15,708 16,500 17,850 18,700 19,250 19,635 23,100 23,375 25,500 26,180 28,050 28,875 29,750 32,725 35,700 38,500 39,270 44,625 46,750 56,100 57,750 59,500 65,450 70,125 78,540 89,250 93,500 98,175 115,500 130,900 140,250 163,625 178,500 196,350 280,500 327,250 392,700 490,875 654,500 981,750 and 1,963,500, with no remainder.
Since 1,963,500 cannot be divided by just 1 and 1,963,500, it is not a prime number.