![[x, x] FactorPairs](../images/logo.png){kind=logo}
Factor Pairs of 81 Perfect Square
All Factor Pairs of 81
Here are all the factor pairs of 81:
(1, 81)
(3, 27)
(9, 9)
Total: 3 factor pairs
Visual Representation of Factors
These are all the factors of 81:
1
3
9
27
81
Properties of 81
Number Type
Deficient Number
Sum of All Factors
121
Sum of Proper Divisors
40
Total Factors
5
Prime Factorization
34
Perfect Square?
Yes
How to Calculate Factor Pairs of 81
Step-by-Step Process
To find all factor pairs of 81, we need to identify all integers that divide 81 evenly (with no remainder).
- Start with the smallest factor, which is always 1
- Check each integer from 1 up to the square root of 81 (v81 ≈ 9.00)
- For each factor found, its corresponding pair is calculated by dividing 81 by that factor
Calculation Example
Let's work through finding the factor pairs of 81:
| Factor Check | Division | Result | Factor Pair |
|---|---|---|---|
| 81 ÷ 1 | 81.00 | Integer result | (1, 81) |
| 81 ÷ 2 | 40.50 | Not a divisor | - |
| 81 ÷ 3 | 27.00 | Integer result | (3, 27) |
| 81 ÷ 4 | 20.25 | Not a divisor | - |
| 81 ÷ 5 | 16.20 | Not a divisor | - |
| 81 ÷ 6 | 13.50 | Not a divisor | - |
| 81 ÷ 7 | 11.57 | Not a divisor | - |
| 81 ÷ 8 | 10.13 | Not a divisor | - |
| 81 ÷ 9 | 9.00 | Integer result | (9, 9) |
Explore More Factor Pairs
Check out factor pairs of these randomly selected numbers:
| Number | Factor Pairs | Total Pairs | Details |
|---|---|---|---|
| 8 | (1, 8), (2, 4) | 2 | View Details |
| 12 | (1, 12), (2, 6), (3, 4) | 3 | View Details |
| 21 | (1, 21), (3, 7) | 2 | View Details |
| 36 | (1, 36), (2, 18), (3, 12), (4, 9), (6, 6) | 5 | View Details |
| 77 | (1, 77), (7, 11) | 2 | View Details |
| 120 | (1, 120), (2, 60), (3, 40), (4, 30), (5, 24), (6, 20), (8, 15), (10, 12) | 8 | View Details |
This table refreshes with new examples each time you visit.
Calculate Factor Pairs of Another Number
More About Deficient Numbers
Deficient Numbers
A deficient number is a positive integer for which the sum of its proper divisors is less than the number itself. The number 81 is deficient because the sum of its proper divisors (40) is less than 81.
All prime numbers are deficient since their only proper divisor is 1.