A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6864060 can be evenly divided by 1 2 3 4 5 6 7 10 12 14 15 20 21 28 30 35 42 59 60 70 84 105 118 140 177 210 236 277 295 354 413 420 554 590 708 826 831 885 1,108 1,180 1,239 1,385 1,652 1,662 1,770 1,939 2,065 2,478 2,770 3,324 3,540 3,878 4,130 4,155 4,956 5,540 5,817 6,195 7,756 8,260 8,310 9,695 11,634 12,390 16,343 16,620 19,390 23,268 24,780 29,085 32,686 38,780 49,029 58,170 65,372 81,715 98,058 114,401 116,340 163,430 196,116 228,802 245,145 326,860 343,203 457,604 490,290 572,005 686,406 980,580 1,144,010 1,372,812 1,716,015 2,288,020 3,432,030 and 6,864,060, with no remainder.
Since 6,864,060 cannot be divided by just 1 and 6,864,060, it is not a prime number.