How can you find a number with thirteen factors?

Answer 1

A factor is a number that can be multiplied by another whole number to equal your original number.

For example: The factors of 10 are - 1, 2, 5, 10 (10 has 4 unique factors)

To find a number with 13 factors, it must be fairly large.

We know the number you're looking for will have at least 2 factors, 1 and itself.

So we only need to find 11 more.

In fact, we can choose factors and make the number ourselves!

Remember, factors must be unique. They cannot repeat. A handy way to do this is to use prime numbers.

1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, and our number. (13 factors)

To find your number, multiply ALL of the prime numbers together. (Not 1, and not our number)

2*3*5*7*11*13*17*19*23*29*31 = ???

You'll find that the number you're looking for is

200,560,490,130

In fact, this number is the smallest composite number with the first 11 primes as factors!