Q: Is 780,400 a Prime Number?
A: No, 780,400 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 780400 can be evenly divided by 1 2 4 5 8 10 16 20 25 40 50 80 100 200 400 1,951 3,902 7,804 9,755 15,608 19,510 31,216 39,020 48,775 78,040 97,550 156,080 195,100 390,200 and 780,400, with no remainder.
Since 780,400 cannot be divided by just 1 and 780,400, it is not a prime number.