A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8552964 can be evenly divided by 1 2 3 4 6 7 12 14 19 21 23 28 38 42 46 57 69 76 84 92 114 133 138 161 228 233 266 276 322 399 437 466 483 532 644 699 798 874 932 966 1,311 1,398 1,596 1,631 1,748 1,932 2,622 2,796 3,059 3,262 4,427 4,893 5,244 5,359 6,118 6,524 8,854 9,177 9,786 10,718 12,236 13,281 16,077 17,708 18,354 19,572 21,436 26,562 30,989 32,154 36,708 37,513 53,124 61,978 64,308 75,026 92,967 101,821 112,539 123,956 150,052 185,934 203,642 225,078 305,463 371,868 407,284 450,156 610,926 712,747 1,221,852 1,425,494 2,138,241 2,850,988 4,276,482 and 8,552,964, with no remainder.
Since 8,552,964 cannot be divided by just 1 and 8,552,964, it is not a prime number.