A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6454560 can be evenly divided by 1 2 3 4 5 6 7 8 10 12 14 15 16 17 20 21 24 28 30 32 34 35 40 42 48 51 56 60 68 70 80 84 85 96 102 105 112 113 119 120 136 140 160 168 170 204 210 224 226 238 240 255 272 280 336 339 340 357 408 420 452 476 480 510 544 560 565 595 672 678 680 714 791 816 840 904 952 1,020 1,120 1,130 1,190 1,356 1,360 1,428 1,582 1,632 1,680 1,695 1,785 1,808 1,904 1,921 2,040 2,260 2,373 2,380 2,712 2,720 2,856 3,164 3,360 3,390 3,570 3,616 3,808 3,842 3,955 4,080 4,520 4,746 4,760 5,424 5,712 5,763 6,328 6,780 7,140 7,684 7,910 8,160 9,040 9,492 9,520 9,605 10,848 11,424 11,526 11,865 12,656 13,447 13,560 14,280 15,368 15,820 18,080 18,984 19,040 19,210 23,052 23,730 25,312 26,894 27,120 28,560 28,815 30,736 31,640 37,968 38,420 40,341 46,104 47,460 53,788 54,240 57,120 57,630 61,472 63,280 67,235 75,936 76,840 80,682 92,208 94,920 107,576 115,260 126,560 134,470 153,680 161,364 184,416 189,840 201,705 215,152 230,520 268,940 307,360 322,728 379,680 403,410 430,304 461,040 537,880 645,456 806,820 922,080 1,075,760 1,290,912 1,613,640 2,151,520 3,227,280 and 6,454,560, with no remainder.
Since 6,454,560 cannot be divided by just 1 and 6,454,560, it is not a prime number.