A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3575754 can be evenly divided by 1 2 3 6 7 9 13 14 18 21 26 37 39 42 59 63 74 78 91 111 117 118 126 177 182 222 234 259 273 333 354 413 481 518 531 546 666 767 777 819 826 962 1,062 1,239 1,443 1,534 1,554 1,638 2,183 2,301 2,331 2,478 2,886 3,367 3,717 4,329 4,366 4,602 4,662 5,369 6,549 6,734 6,903 7,434 8,658 10,101 10,738 13,098 13,806 15,281 16,107 19,647 20,202 28,379 30,303 30,562 32,214 39,294 45,843 48,321 56,758 60,606 85,137 91,686 96,642 137,529 170,274 198,653 255,411 275,058 397,306 510,822 595,959 1,191,918 1,787,877 and 3,575,754, with no remainder.
Since 3,575,754 cannot be divided by just 1 and 3,575,754, it is not a prime number.