A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4646304 can be evenly divided by 1 2 3 4 6 8 9 12 13 16 17 18 24 26 32 34 36 39 48 51 52 68 72 73 78 96 102 104 117 136 144 146 153 156 204 208 219 221 234 272 288 292 306 312 408 416 438 442 468 544 584 612 624 657 663 816 876 884 936 949 1,168 1,224 1,241 1,248 1,314 1,326 1,632 1,752 1,768 1,872 1,898 1,989 2,336 2,448 2,482 2,628 2,652 2,847 3,504 3,536 3,723 3,744 3,796 3,978 4,896 4,964 5,256 5,304 5,694 7,008 7,072 7,446 7,592 7,956 8,541 9,928 10,512 10,608 11,169 11,388 14,892 15,184 15,912 16,133 17,082 19,856 21,024 21,216 22,338 22,776 29,784 30,368 31,824 32,266 34,164 39,712 44,676 45,552 48,399 59,568 63,648 64,532 68,328 89,352 91,104 96,798 119,136 129,064 136,656 145,197 178,704 193,596 258,128 273,312 290,394 357,408 387,192 516,256 580,788 774,384 1,161,576 1,548,768 2,323,152 and 4,646,304, with no remainder.
Since 4,646,304 cannot be divided by just 1 and 4,646,304, it is not a prime number.