Q: Is 551,421 a Prime Number?
A: No, 551,421 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 551421 can be evenly divided by 1 3 9 13 27 39 117 351 1,571 4,713 14,139 20,423 42,417 61,269 183,807 and 551,421, with no remainder.
Since 551,421 cannot be divided by just 1 and 551,421, it is not a prime number.