A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6850380 can be evenly divided by 1 2 3 4 5 6 10 12 15 20 29 30 31 58 60 62 87 93 116 124 127 145 155 174 186 254 290 310 348 372 381 435 465 508 580 620 635 762 870 899 930 1,270 1,524 1,740 1,798 1,860 1,905 2,540 2,697 3,596 3,683 3,810 3,937 4,495 5,394 7,366 7,620 7,874 8,990 10,788 11,049 11,811 13,485 14,732 15,748 17,980 18,415 19,685 22,098 23,622 26,970 36,830 39,370 44,196 47,244 53,940 55,245 59,055 73,660 78,740 110,490 114,173 118,110 220,980 228,346 236,220 342,519 456,692 570,865 685,038 1,141,730 1,370,076 1,712,595 2,283,460 3,425,190 and 6,850,380, with no remainder.
Since 6,850,380 cannot be divided by just 1 and 6,850,380, it is not a prime number.