Q: Is 555,555 a Composite Number?

Why is 555,555 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 555,555 can be evenly divided by 1 3 5 7 11 13 15 21 33 35 37 39 55 65 77 91 105 111 143 165 185 195 231 259 273 385 407 429 455 481 555 715 777 1,001 1,155 1,221 1,295 1,365 1,443 2,035 2,145 2,405 2,849 3,003 3,367 3,885 5,005 5,291 6,105 7,215 8,547 10,101 14,245 15,015 15,873 16,835 26,455 37,037 42,735 50,505 79,365 111,111 185,185 and 555,555, with no remainder.

Since 555,555 cannot be divided by just 1 and 555,555, 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).