A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 9420516 can be evenly divided by 1 2 3 4 6 7 9 12 14 17 18 21 27 28 34 36 42 51 54 63 68 84 102 108 119 126 153 189 204 238 252 306 357 378 459 476 612 714 733 756 918 1,071 1,428 1,466 1,836 2,142 2,199 2,932 3,213 4,284 4,398 5,131 6,426 6,597 8,796 10,262 12,461 12,852 13,194 15,393 19,791 20,524 24,922 26,388 30,786 37,383 39,582 46,179 49,844 61,572 74,766 79,164 87,227 92,358 112,149 138,537 149,532 174,454 184,716 224,298 261,681 277,074 336,447 348,908 448,596 523,362 554,148 672,894 785,043 1,046,724 1,345,788 1,570,086 2,355,129 3,140,172 4,710,258 and 9,420,516, with no remainder.
Since 9,420,516 cannot be divided by just 1 and 9,420,516, it is not a prime number.