A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 6850872 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 18 21 23 24 27 28 36 42 46 54 56 63 69 72 84 92 108 126 138 161 168 184 189 197 207 216 252 276 322 378 394 414 483 504 552 591 621 644 756 788 828 966 1,182 1,242 1,288 1,379 1,449 1,512 1,576 1,656 1,773 1,932 2,364 2,484 2,758 2,898 3,546 3,864 4,137 4,347 4,531 4,728 4,968 5,319 5,516 5,796 7,092 8,274 8,694 9,062 10,638 11,032 11,592 12,411 13,593 14,184 16,548 17,388 18,124 21,276 24,822 27,186 31,717 33,096 34,776 36,248 37,233 40,779 42,552 49,644 54,372 63,434 74,466 81,558 95,151 99,288 108,744 122,337 126,868 148,932 163,116 190,302 244,674 253,736 285,453 297,864 326,232 380,604 489,348 570,906 761,208 856,359 978,696 1,141,812 1,712,718 2,283,624 3,425,436 and 6,850,872, with no remainder.
Since 6,850,872 cannot be divided by just 1 and 6,850,872, it is not a prime number.