A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 9120510 can be evenly divided by 1 2 3 5 6 7 9 10 14 15 18 21 30 31 35 42 45 62 63 70 90 93 105 126 155 186 210 217 279 310 315 434 465 467 558 630 651 930 934 1,085 1,302 1,395 1,401 1,953 2,170 2,335 2,790 2,802 3,255 3,269 3,906 4,203 4,670 6,510 6,538 7,005 8,406 9,765 9,807 14,010 14,477 16,345 19,530 19,614 21,015 28,954 29,421 32,690 42,030 43,431 49,035 58,842 72,385 86,862 98,070 101,339 130,293 144,770 147,105 202,678 217,155 260,586 294,210 304,017 434,310 506,695 608,034 651,465 912,051 1,013,390 1,302,930 1,520,085 1,824,102 3,040,170 4,560,255 and 9,120,510, with no remainder.
Since 9,120,510 cannot be divided by just 1 and 9,120,510, it is not a prime number.