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What are Factors?

Visual representation of factors of 63
Visualizing factors as equal groups

Factors are numbers that divide evenly into another number without leaving a remainder. For example, the factors of 63 are the numbers that multiply together to give 63.

Think of factors as the numbers that perfectly fit into 63 when we divide. For instance:

63 ÷ 7 = 9 (with no remainder), so 7 is a factor of 63.
63 ÷ 8 = 7.875 (not a whole number), so 8 is not a factor.

1
3
7
9
21
63

How to Find Factors of 63

Step-by-step guide to finding factors
Visual guide to finding factors

There are two main methods to find factors of a number: the division method and the multiplication method.

Division Method

Divide 63 by whole numbers starting from 1 up to 63. If the division gives a whole number result with no remainder, both the divisor and the quotient are factors.

Division Result Is Factor?
63 ÷ 163Yes (1 and 63)
63 ÷ 231.5No
63 ÷ 321Yes (3 and 21)
63 ÷ 415.75No
63 ÷ 512.6No
63 ÷ 610.5No
63 ÷ 79Yes (7 and 9)

Prime Factorization of 63

Factor tree of 63
Factor tree showing prime factors

Prime factorization means breaking down a number into its prime factors. Prime factors are prime numbers that multiply together to make the original number.

We can use a factor tree to find the prime factors of 63:

  • 63
    • 9
      • 3
      • 3
    • 7

From this factor tree, we see that:

63 = 3 × 3 × 7

or written with exponents: 63 = 3² × 7

Factor Pairs of 63

Visual representation of factor pairs
Factor pairs arranged visually

Factor pairs are two numbers that multiply together to give the original number. For 63, we have both positive and negative factor pairs.

Positive Factor Pairs

1 × 63
3 × 21
7 × 9
9 × 7
21 × 3
63 × 1

Negative Factor Pairs

Negative factors also exist because multiplying two negative numbers gives a positive product:

(-1) × (-63)
(-3) × (-21)
(-7) × (-9)
(-9) × (-7)
(-21) × (-3)
(-63) × (-1)

Factors of 63 Quiz

Test your knowledge about factors of 63 with this 5-question quiz.

1. Which of these is NOT a factor of 63?
2. What is the prime factorization of 63?
3. Which factor pair multiplies to 63?
4. How many factors does 63 have?
5. What is the sum of all factors of 63?

Frequently Asked Questions

Here are answers to common questions about factors of 63:

Math Trivia

Discover interesting facts about numbers and factors:

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