A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5310120 can be evenly divided by 1 2 3 4 5 6 8 10 12 15 17 19 20 24 30 34 38 40 51 57 60 68 76 85 95 102 114 120 136 137 152 170 190 204 228 255 274 285 323 340 380 408 411 456 510 548 570 646 680 685 760 822 969 1,020 1,096 1,140 1,292 1,370 1,615 1,644 1,938 2,040 2,055 2,280 2,329 2,584 2,603 2,740 3,230 3,288 3,876 4,110 4,658 4,845 5,206 5,480 6,460 6,987 7,752 7,809 8,220 9,316 9,690 10,412 11,645 12,920 13,015 13,974 15,618 16,440 18,632 19,380 20,824 23,290 26,030 27,948 31,236 34,935 38,760 39,045 44,251 46,580 52,060 55,896 62,472 69,870 78,090 88,502 93,160 104,120 132,753 139,740 156,180 177,004 221,255 265,506 279,480 312,360 354,008 442,510 531,012 663,765 885,020 1,062,024 1,327,530 1,770,040 2,655,060 and 5,310,120, with no remainder.
Since 5,310,120 cannot be divided by just 1 and 5,310,120, it is not a prime number.