How many positive integers are factors of 20. How to find all positive factors of 20? Is 20 a prime or a composit number? How to find factors of 20.
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1 Answer

The factors of the number 20 are: 20, 10, 5, 4, 2, 1

The square root of 20 rounded up to the nearest integer is 5. This is the limit to test our divisions because any number greater than 5 times 5 is greater than 20. So, we stop at 5.

Let's test the values 1 through 5 for division into 20.

  • 20/1 = 20. Remainder = 0. So, 20 and 1 are factors.
  • 20/2 = 10. Remainder = 0. So, 10 and 2 are factors.
  • 20/3 = 6. Remainder = 2. So, 6 isn't a factor.
  • 20/4 = 5. Remainder = 0. So, 5 and 4 are factors.
  • 20/5 = 4. Remainder = 0. So, 4 and 5 are factors.

Factors of a number n are numbers that can divide n without remainder, ie, remainder = 0. So, choosing only the numbers that meet this criteria from the list above, we find that the numbers which divide 20 (including 20) with no remainder are: 20, 10, 5, 4, 2, 1.

So, the factors of the number 20 are: 20, 10, 5, 4, 2, 1.

A composite number has more than two factors. A prime number has only two factors: 1 and itself. The number 1 is neither prime nor composite.

Because the number 20 has 6 factors, it is termed a composite number in mathematics.

As 20 is a composite number, we can factorize it, ie, express it in prime Factors as follows.

By factorizing 20 we get: 20 = 2 * 2 * 5.

Ie, 20 can be expressed as a product (factor string) of prime numbers (2 2 5).

answered by expert