Q: Is 821,205 a Composite Number?

Why is 821,205 a composite number?

A composite number is a number that can be divided evenly by more numbers than 1 and itself. It is the opposite of a prime number.

The number 821,205 can be evenly divided by 1 3 5 7 9 11 15 21 27 33 35 45 55 63 77 79 99 105 135 165 189 231 237 297 315 385 395 495 553 693 711 869 945 1,155 1,185 1,485 1,659 2,079 2,133 2,607 2,765 3,465 3,555 4,345 4,977 6,083 7,821 8,295 10,395 10,665 13,035 14,931 18,249 23,463 24,885 30,415 39,105 54,747 74,655 91,245 117,315 164,241 273,735 and 821,205, with no remainder.

Since 821,205 cannot be divided by just 1 and 821,205, it is a composite number.

More Examples

• All positive natural numbers are either a prime number or a composite number (except the number 1, which is neither).