Q: Is 780,640 a Prime Number?
A: No, 780,640 is not a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 780640 can be evenly divided by 1 2 4 5 7 8 10 14 16 17 20 28 32 34 35 40 41 56 68 70 80 82 85 112 119 136 140 160 164 170 205 224 238 272 280 287 328 340 410 476 544 560 574 595 656 680 697 820 952 1,120 1,148 1,190 1,312 1,360 1,394 1,435 1,640 1,904 2,296 2,380 2,720 2,788 2,870 3,280 3,485 3,808 4,592 4,760 4,879 5,576 5,740 6,560 6,970 9,184 9,520 9,758 11,152 11,480 13,940 19,040 19,516 22,304 22,960 24,395 27,880 39,032 45,920 48,790 55,760 78,064 97,580 111,520 156,128 195,160 390,320 and 780,640, with no remainder.
Since 780,640 cannot be divided by just 1 and 780,640, it is not a prime number.