A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 800730 can be evenly divided by 1 2 3 5 6 7 9 10 14 15 18 21 30 31 35 41 42 45 62 63 70 82 90 93 105 123 126 155 186 205 210 217 246 279 287 310 315 369 410 434 465 558 574 615 630 651 738 861 930 1,085 1,230 1,271 1,302 1,395 1,435 1,722 1,845 1,953 2,170 2,542 2,583 2,790 2,870 3,255 3,690 3,813 3,906 4,305 5,166 6,355 6,510 7,626 8,610 8,897 9,765 11,439 12,710 12,915 17,794 19,065 19,530 22,878 25,830 26,691 38,130 44,485 53,382 57,195 80,073 88,970 114,390 133,455 160,146 266,910 400,365 and 800,730, with no remainder.
Since 800,730 cannot be divided by just 1 and 800,730, it is not a prime number.