Q: Is 405,405 a Composite Number?

Why is 405,405 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 405,405 can be evenly divided by 1 3 5 7 9 11 13 15 21 27 33 35 39 45 55 63 65 77 81 91 99 105 117 135 143 165 189 195 231 273 297 315 351 385 405 429 455 495 567 585 693 715 819 891 945 1,001 1,053 1,155 1,287 1,365 1,485 1,755 2,079 2,145 2,457 2,835 3,003 3,465 3,861 4,095 4,455 5,005 5,265 6,237 6,435 7,371 9,009 10,395 11,583 12,285 15,015 19,305 27,027 31,185 36,855 45,045 57,915 81,081 135,135 and 405,405, with no remainder.

Since 405,405 cannot be divided by just 1 and 405,405, 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).