The number 9 has several interesting factors that contribute to its mathematical properties. Here are some key factors of the number 9:

- Divisible by 1 and itself: Like all natural numbers, 9 is divisible by 1 and itself (9 ÷ 1 = 9 and 9 ÷ 9 = 1).
- Multiplication table: 9 has a unique pattern in its multiplication table. When you multiply 9 by any single-digit number (from 1 to 9), the digits in the result always add up to 9. For example, 9 × 2 = 18 (1 + 8 = 9) and 9 × 7 = 63 (6 + 3 = 9). This property is often used to perform mental calculations and is known as the “digit sum” or “casting out nines” property.
- Composite number: 9 is a composite number, meaning it has factors other than 1 and itself. In the case of 9, its factors are 1, 3, and 9. A composite number is the opposite of a prime number, which only has two factors: 1 and itself.
- Perfect square: 9 is a perfect square because it can be expressed as the square of a whole number. In this case, 9 is the square of 3 (3 × 3 = 9). Perfect squares have the interesting property that their square roots are also whole numbers.

These are some of the key factors and properties of the number 9. Understanding these factors can help in various mathematical calculations and analyses involving the number 9.

## How many Factors of 9

The number 9 has a total of 3 factors. The factors of 9 are 1, 3, and 9.

#### Factor Pairs of 9

The factor pairs of 9 are the pairs of numbers that, when multiplied together, result in 9. In the case of 9, the factor pairs are:

1 × 9 = 9

3 × 3 = 9

So, the factor pairs of 9 are (1, 9) and (3, 3).

#### All Factors of 9 using Multiplication

To find all the factors of 9 using multiplication, we can start by listing all the possible combinations of numbers that, when multiplied together, result in 9.

1 × 9 = 9

3 × 3 = 9

Therefore, the factors of 9 using multiplication are 1, 3, and 9.