A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6066240 can be evenly divided by 1 2 3 4 5 6 8 10 12 15 16 20 24 30 32 40 48 60 64 71 80 89 96 120 142 160 178 192 213 240 267 284 320 355 356 426 445 480 534 568 710 712 852 890 960 1,065 1,068 1,136 1,335 1,420 1,424 1,704 1,780 2,130 2,136 2,272 2,670 2,840 2,848 3,408 3,560 4,260 4,272 4,544 5,340 5,680 5,696 6,319 6,816 7,120 8,520 8,544 10,680 11,360 12,638 13,632 14,240 17,040 17,088 18,957 21,360 22,720 25,276 28,480 31,595 34,080 37,914 42,720 50,552 63,190 68,160 75,828 85,440 94,785 101,104 126,380 151,656 189,570 202,208 252,760 303,312 379,140 404,416 505,520 606,624 758,280 1,011,040 1,213,248 1,516,560 2,022,080 3,033,120 and 6,066,240, with no remainder.
Since 6,066,240 cannot be divided by just 1 and 6,066,240, it is not a prime number.