A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 246960 can be evenly divided by 1 2 3 4 5 6 7 8 9 10 12 14 15 16 18 20 21 24 28 30 35 36 40 42 45 48 49 56 60 63 70 72 80 84 90 98 105 112 120 126 140 144 147 168 180 196 210 240 245 252 280 294 315 336 343 360 392 420 441 490 504 560 588 630 686 720 735 784 840 882 980 1,008 1,029 1,176 1,260 1,372 1,470 1,680 1,715 1,764 1,960 2,058 2,205 2,352 2,520 2,744 2,940 3,087 3,430 3,528 3,920 4,116 4,410 5,040 5,145 5,488 5,880 6,174 6,860 7,056 8,232 8,820 10,290 11,760 12,348 13,720 15,435 16,464 17,640 20,580 24,696 27,440 30,870 35,280 41,160 49,392 61,740 82,320 123,480 and 246,960, with no remainder.
Since 246,960 cannot be divided by just 1 and 246,960, it is not a prime number.