Q: Is 621,820 a Prime Number?
A: No, 621,820 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 621820 can be evenly divided by 1 2 4 5 10 20 31,091 62,182 124,364 155,455 310,910 and 621,820, with no remainder.
Since 621,820 cannot be divided by just 1 and 621,820, it is not a prime number.