A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 1845060 can be evenly divided by 1 2 3 4 5 6 7 10 12 14 15 20 21 23 28 30 35 42 46 60 69 70 84 92 105 115 138 140 161 191 210 230 276 322 345 382 420 460 483 573 644 690 764 805 955 966 1,146 1,337 1,380 1,610 1,910 1,932 2,292 2,415 2,674 2,865 3,220 3,820 4,011 4,393 4,830 5,348 5,730 6,685 8,022 8,786 9,660 11,460 13,179 13,370 16,044 17,572 20,055 21,965 26,358 26,740 30,751 40,110 43,930 52,716 61,502 65,895 80,220 87,860 92,253 123,004 131,790 153,755 184,506 263,580 307,510 369,012 461,265 615,020 922,530 and 1,845,060, with no remainder.
Since 1,845,060 cannot be divided by just 1 and 1,845,060, it is not a prime number.