A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5771808 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 16 18 21 24 28 32 36 42 48 49 56 63 72 84 96 98 112 126 144 147 168 196 224 252 288 294 336 392 409 441 504 588 672 784 818 882 1,008 1,176 1,227 1,568 1,636 1,764 2,016 2,352 2,454 2,863 3,272 3,528 3,681 4,704 4,908 5,726 6,544 7,056 7,362 8,589 9,816 11,452 13,088 14,112 14,724 17,178 19,632 20,041 22,904 25,767 29,448 34,356 39,264 40,082 45,808 51,534 58,896 60,123 68,712 80,164 91,616 103,068 117,792 120,246 137,424 160,328 180,369 206,136 240,492 274,848 320,656 360,738 412,272 480,984 641,312 721,476 824,544 961,968 1,442,952 1,923,936 2,885,904 and 5,771,808, with no remainder.
Since 5,771,808 cannot be divided by just 1 and 5,771,808, it is not a prime number.