A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7191600 can be evenly divided by 1 2 3 4 5 6 8 10 12 13 15 16 20 24 25 26 30 39 40 48 50 52 60 65 75 78 80 100 104 120 130 150 156 195 200 208 240 260 300 312 325 390 400 461 520 600 624 650 780 922 975 1,040 1,200 1,300 1,383 1,560 1,844 1,950 2,305 2,600 2,766 3,120 3,688 3,900 4,610 5,200 5,532 5,993 6,915 7,376 7,800 9,220 11,064 11,525 11,986 13,830 15,600 17,979 18,440 22,128 23,050 23,972 27,660 29,965 34,575 35,958 36,880 46,100 47,944 55,320 59,930 69,150 71,916 89,895 92,200 95,888 110,640 119,860 138,300 143,832 149,825 179,790 184,400 239,720 276,600 287,664 299,650 359,580 449,475 479,440 553,200 599,300 719,160 898,950 1,198,600 1,438,320 1,797,900 2,397,200 3,595,800 and 7,191,600, with no remainder.
Since 7,191,600 cannot be divided by just 1 and 7,191,600, it is not a prime number.