Generate Almost Perfect Numbers

This tool creates a list of almost perfect numbers based on how many you want to see. An almost perfect number is one where the sum of its proper divisors is exactly one less than the number itself. Classic examples include 1, 2, 4, 8, and so on. The output updates instantly as you type, and you can format it to suit your workflow with live toggles.

It’s interactive, cleanly styled, and gives you export and copy options in one click.

Total items: 0
Options
Line-by-line output
Show index numbers

How to Use:

  1. Enter the number of almost perfect numbers to generate.
  2. Use the toggles to control layout:
    • Line-by-line or inline output
    • Show index numbers or not
  3. Results update instantly in the output box.
  4. Click “Copy Output” to copy to clipboard.
  5. Click “Export to File” to download as a .txt file.
  6. Use “Clear All” to reset everything back to blank.

What Generate Almost Perfect Numbers can do:

This tool finds numbers where the proper divisors add up to exactly one less than the number. Unlike perfect numbers (where the divisors equal the number), almost perfect numbers show a slightly different kind of symmetry. The most famous is 1, followed by all powers of 2 up to very large values.

You can switch between line view and comma-separated view, and optionally add index numbers if you’re comparing positions. The flashing preview lets you know output updated, and the counter confirms how many numbers were generated.

Example:

Input:

10

Settings: Line-by-line: ON, Show index: OFF

Output:

1
2
4
8
16
32
64
128
256
512

Common Use Cases:

Use it when you’re exploring number theory, studying divisor sums, or working with power-of-two patterns. Almost perfect numbers are useful in math education, algorithm testing, and anywhere you want a clean example of nearly self-equalizing sums. It’s a lightweight, no-reload tool for fast exploration.

Useful Tools & Suggestions:

Almost perfect numbers are rare, so it helps to see how they differ from the real deal Generate Perfect Numbers gives you that full match for comparison. And if you want to explore the other side, Generate Deficient Number Sequence shows numbers that fall short by more than just one.

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