A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 417312 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 16 18 21 23 24 27 28 32 36 42 46 48 54 56 63 69 72 81 84 92 96 108 112 126 138 144 161 162 168 184 189 207 216 224 252 276 288 322 324 336 368 378 414 432 483 504 552 567 621 644 648 672 736 756 828 864 966 1,008 1,104 1,134 1,242 1,288 1,296 1,449 1,512 1,656 1,863 1,932 2,016 2,208 2,268 2,484 2,576 2,592 2,898 3,024 3,312 3,726 3,864 4,347 4,536 4,968 5,152 5,796 6,048 6,624 7,452 7,728 8,694 9,072 9,936 11,592 13,041 14,904 15,456 17,388 18,144 19,872 23,184 26,082 29,808 34,776 46,368 52,164 59,616 69,552 104,328 139,104 208,656 and 417,312, with no remainder.
Since 417,312 cannot be divided by just 1 and 417,312, it is not a prime number.