A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 9145620 can be evenly divided by 1 2 3 4 5 6 9 10 11 12 15 18 20 22 30 31 33 36 44 45 55 60 62 66 90 93 99 110 124 132 149 155 165 180 186 198 220 279 298 310 330 341 372 396 447 465 495 558 596 620 660 682 745 894 930 990 1,023 1,116 1,341 1,364 1,395 1,490 1,639 1,705 1,788 1,860 1,980 2,046 2,235 2,682 2,790 2,980 3,069 3,278 3,410 4,092 4,470 4,619 4,917 5,115 5,364 5,580 6,138 6,556 6,705 6,820 8,195 8,940 9,238 9,834 10,230 12,276 13,410 13,857 14,751 15,345 16,390 18,476 19,668 20,460 23,095 24,585 26,820 27,714 29,502 30,690 32,780 41,571 46,190 49,170 50,809 55,428 59,004 61,380 69,285 73,755 83,142 92,380 98,340 101,618 138,570 147,510 152,427 166,284 203,236 207,855 254,045 277,140 295,020 304,854 415,710 457,281 508,090 609,708 762,135 831,420 914,562 1,016,180 1,524,270 1,829,124 2,286,405 3,048,540 4,572,810 and 9,145,620, with no remainder.
Since 9,145,620 cannot be divided by just 1 and 9,145,620, it is not a prime number.