A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 364140 can be evenly divided by 1 2 3 4 5 6 7 9 10 12 14 15 17 18 20 21 28 30 34 35 36 42 45 51 60 63 68 70 84 85 90 102 105 119 126 140 153 170 180 204 210 238 252 255 289 306 315 340 357 420 476 510 578 595 612 630 714 765 867 1,020 1,071 1,156 1,190 1,260 1,428 1,445 1,530 1,734 1,785 2,023 2,142 2,380 2,601 2,890 3,060 3,468 3,570 4,046 4,284 4,335 5,202 5,355 5,780 6,069 7,140 8,092 8,670 10,115 10,404 10,710 12,138 13,005 17,340 18,207 20,230 21,420 24,276 26,010 30,345 36,414 40,460 52,020 60,690 72,828 91,035 121,380 182,070 and 364,140, with no remainder.
Since 364,140 cannot be divided by just 1 and 364,140, it is not a prime number.