A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6256500 can be evenly divided by 1 2 3 4 5 6 10 12 15 20 25 30 43 50 60 75 86 97 100 125 129 150 172 194 215 250 258 291 300 375 388 430 485 500 516 582 645 750 860 970 1,075 1,164 1,290 1,455 1,500 1,940 2,150 2,425 2,580 2,910 3,225 4,171 4,300 4,850 5,375 5,820 6,450 7,275 8,342 9,700 10,750 12,125 12,513 12,900 14,550 16,125 16,684 20,855 21,500 24,250 25,026 29,100 32,250 36,375 41,710 48,500 50,052 62,565 64,500 72,750 83,420 104,275 125,130 145,500 208,550 250,260 312,825 417,100 521,375 625,650 1,042,750 1,251,300 1,564,125 2,085,500 3,128,250 and 6,256,500, with no remainder.
Since 6,256,500 cannot be divided by just 1 and 6,256,500, it is not a prime number.