A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6250680 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 20 24 30 36 40 45 60 72 90 97 120 179 180 194 291 358 360 388 485 537 582 716 776 873 895 970 1,074 1,164 1,432 1,455 1,611 1,746 1,790 1,940 2,148 2,328 2,685 2,910 3,222 3,492 3,580 3,880 4,296 4,365 5,370 5,820 6,444 6,984 7,160 8,055 8,730 10,740 11,640 12,888 16,110 17,363 17,460 21,480 32,220 34,726 34,920 52,089 64,440 69,452 86,815 104,178 138,904 156,267 173,630 208,356 260,445 312,534 347,260 416,712 520,890 625,068 694,520 781,335 1,041,780 1,250,136 1,562,670 2,083,560 3,125,340 and 6,250,680, with no remainder.
Since 6,250,680 cannot be divided by just 1 and 6,250,680, it is not a prime number.