A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 5861880 can be evenly divided by 1 2 3 4 5 6 8 9 10 12 15 18 19 20 24 30 36 38 40 45 57 60 72 76 90 95 114 120 152 171 180 190 228 285 342 360 380 456 570 684 760 855 857 1,140 1,368 1,710 1,714 2,280 2,571 3,420 3,428 4,285 5,142 6,840 6,856 7,713 8,570 10,284 12,855 15,426 16,283 17,140 20,568 25,710 30,852 32,566 34,280 38,565 48,849 51,420 61,704 65,132 77,130 81,415 97,698 102,840 130,264 146,547 154,260 162,830 195,396 244,245 293,094 308,520 325,660 390,792 488,490 586,188 651,320 732,735 976,980 1,172,376 1,465,470 1,953,960 2,930,940 and 5,861,880, with no remainder.
Since 5,861,880 cannot be divided by just 1 and 5,861,880, it is not a prime number.