A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2215360 can be evenly divided by 1 2 4 5 7 8 10 14 16 20 23 28 32 35 40 43 46 56 64 70 80 86 92 112 115 140 160 161 172 184 215 224 230 280 301 320 322 344 368 430 448 460 560 602 644 688 736 805 860 920 989 1,120 1,204 1,288 1,376 1,472 1,505 1,610 1,720 1,840 1,978 2,240 2,408 2,576 2,752 3,010 3,220 3,440 3,680 3,956 4,816 4,945 5,152 6,020 6,440 6,880 6,923 7,360 7,912 9,632 9,890 10,304 12,040 12,880 13,760 13,846 15,824 19,264 19,780 24,080 25,760 27,692 31,648 34,615 39,560 48,160 51,520 55,384 63,296 69,230 79,120 96,320 110,768 138,460 158,240 221,536 276,920 316,480 443,072 553,840 1,107,680 and 2,215,360, with no remainder.
Since 2,215,360 cannot be divided by just 1 and 2,215,360, it is not a prime number.