Q: Is 1,638,991 a Composite Number?
A: No, 1,638,991 is not a composite number; it is a prime number.
The number 1,638,991 can be evenly divided by 1 and 1,638,991, with no remainder.
Since 1,638,991 can be divided by just 1 and 1,638,991, it is not a composite number.