A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6155100 can be evenly divided by 1 2 3 4 5 6 7 9 10 12 14 15 18 20 21 25 28 30 35 36 42 45 50 60 63 70 75 84 90 100 105 126 140 150 175 180 210 225 252 300 315 350 420 450 525 630 700 900 977 1,050 1,260 1,575 1,954 2,100 2,931 3,150 3,908 4,885 5,862 6,300 6,839 8,793 9,770 11,724 13,678 14,655 17,586 19,540 20,517 24,425 27,356 29,310 34,195 35,172 41,034 43,965 48,850 58,620 61,551 68,390 73,275 82,068 87,930 97,700 102,585 123,102 136,780 146,550 170,975 175,860 205,170 219,825 246,204 293,100 307,755 341,950 410,340 439,650 512,925 615,510 683,900 879,300 1,025,850 1,231,020 1,538,775 2,051,700 3,077,550 and 6,155,100, with no remainder.
Since 6,155,100 cannot be divided by just 1 and 6,155,100, it is not a prime number.