A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1308060 can be evenly divided by 1 2 3 4 5 6 9 10 12 13 15 18 20 26 30 36 39 43 45 52 60 65 78 86 90 117 129 130 156 169 172 180 195 215 234 258 260 338 387 390 430 468 507 516 559 585 645 676 774 780 845 860 1,014 1,118 1,170 1,290 1,521 1,548 1,677 1,690 1,935 2,028 2,236 2,340 2,535 2,580 2,795 3,042 3,354 3,380 3,870 5,031 5,070 5,590 6,084 6,708 7,267 7,605 7,740 8,385 10,062 10,140 11,180 14,534 15,210 16,770 20,124 21,801 25,155 29,068 30,420 33,540 36,335 43,602 50,310 65,403 72,670 87,204 100,620 109,005 130,806 145,340 218,010 261,612 327,015 436,020 654,030 and 1,308,060, with no remainder.
Since 1,308,060 cannot be divided by just 1 and 1,308,060, it is not a prime number.