What this calculator does
Perfect, abundant & deficient number check works out classifies a whole number by comparing it to the sum of its own proper divisors. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulaσ(n) = sum of proper divisors; equal to n → perfect, greater → abundant, less → deficient
The inputs explained
| Field | What to enter |
|---|---|
| Whole number | A number. Starts at 28. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with whole number
Every other input is held at the calculator’s starting values while whole number varies. Select any row to load that scenario into the calculator.