A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1953900 can be evenly divided by 1 2 3 4 5 6 9 10 12 13 15 18 20 25 26 30 36 39 45 50 52 60 65 75 78 90 100 117 130 150 156 167 180 195 225 234 260 300 325 334 390 450 468 501 585 650 668 780 835 900 975 1,002 1,170 1,300 1,503 1,670 1,950 2,004 2,171 2,340 2,505 2,925 3,006 3,340 3,900 4,175 4,342 5,010 5,850 6,012 6,513 7,515 8,350 8,684 10,020 10,855 11,700 12,525 13,026 15,030 16,700 19,539 21,710 25,050 26,052 30,060 32,565 37,575 39,078 43,420 50,100 54,275 65,130 75,150 78,156 97,695 108,550 130,260 150,300 162,825 195,390 217,100 325,650 390,780 488,475 651,300 976,950 and 1,953,900, with no remainder.
Since 1,953,900 cannot be divided by just 1 and 1,953,900, it is not a prime number.