A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8380064 can be evenly divided by 1 2 4 7 8 11 14 16 19 22 28 32 38 44 56 76 77 88 112 133 152 154 176 179 209 224 266 304 308 352 358 418 532 608 616 716 836 1,064 1,232 1,253 1,432 1,463 1,672 1,969 2,128 2,464 2,506 2,864 2,926 3,344 3,401 3,938 4,256 5,012 5,728 5,852 6,688 6,802 7,876 10,024 11,704 13,604 13,783 15,752 20,048 23,408 23,807 27,208 27,566 31,504 37,411 40,096 46,816 47,614 54,416 55,132 63,008 74,822 95,228 108,832 110,264 149,644 190,456 220,528 261,877 299,288 380,912 441,056 523,754 598,576 761,824 1,047,508 1,197,152 2,095,016 4,190,032 and 8,380,064, with no remainder.
Since 8,380,064 cannot be divided by just 1 and 8,380,064, it is not a prime number.