A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5711706 can be evenly divided by 1 2 3 6 7 9 11 13 14 18 21 22 26 33 39 42 63 66 77 78 91 99 117 126 143 154 182 198 231 234 273 286 317 429 462 546 634 693 819 858 951 1,001 1,287 1,386 1,638 1,902 2,002 2,219 2,574 2,853 3,003 3,487 4,121 4,438 5,706 6,006 6,657 6,974 8,242 9,009 10,461 12,363 13,314 18,018 19,971 20,922 24,409 24,726 28,847 31,383 37,089 39,942 45,331 48,818 57,694 62,766 73,227 74,178 86,541 90,662 135,993 146,454 173,082 219,681 259,623 271,986 317,317 407,979 439,362 519,246 634,634 815,958 951,951 1,903,902 2,855,853 and 5,711,706, with no remainder.
Since 5,711,706 cannot be divided by just 1 and 5,711,706, it is not a prime number.