Q: Is 561,820 a Prime Number?
A: No, 561,820 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 561820 can be evenly divided by 1 2 4 5 7 10 14 20 28 35 70 140 4,013 8,026 16,052 20,065 28,091 40,130 56,182 80,260 112,364 140,455 280,910 and 561,820, with no remainder.
Since 561,820 cannot be divided by just 1 and 561,820, it is not a prime number.