Q: Is 1,621,564 a Prime Number?
A: No, 1,621,564 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 1621564 can be evenly divided by 1 2 4 7 14 28 29 58 116 203 406 812 1,997 3,994 7,988 13,979 27,958 55,916 57,913 115,826 231,652 405,391 810,782 and 1,621,564, with no remainder.
Since 1,621,564 cannot be divided by just 1 and 1,621,564, it is not a prime number.