A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 7385616 can be evenly divided by 1 2 3 4 6 7 8 9 12 14 16 17 18 21 24 28 34 36 42 48 51 56 63 68 72 84 102 112 119 126 136 144 153 168 204 238 252 272 306 336 357 408 431 476 504 612 714 816 862 952 1,008 1,071 1,224 1,293 1,428 1,724 1,904 2,142 2,448 2,586 2,856 3,017 3,448 3,879 4,284 5,172 5,712 6,034 6,896 7,327 7,758 8,568 9,051 10,344 12,068 14,654 15,516 17,136 18,102 20,688 21,981 24,136 27,153 29,308 31,032 36,204 43,962 48,272 51,289 54,306 58,616 62,064 65,943 72,408 87,924 102,578 108,612 117,232 131,886 144,816 153,867 175,848 205,156 217,224 263,772 307,734 351,696 410,312 434,448 461,601 527,544 615,468 820,624 923,202 1,055,088 1,230,936 1,846,404 2,461,872 3,692,808 and 7,385,616, with no remainder.
Since 7,385,616 cannot be divided by just 1 and 7,385,616, it is not a prime number.