Perfect number checker

Client

A perfect number equals the sum of its proper divisors. Try classics like 6 or 28, or explore composites—most fail the test quickly.

How to use

Type a positive integer. The tool sums all proper divisors and compares to n.

About Perfect number checker

Test whether n equals the sum of its proper divisors (6, 28, 496, …)—runs locally up to safe integer limits. The interactive transform on this page runs in your browser tab—Toolcore does not need your paste for the core operation described above.

How to use this page

Paste or type in the main workspace, run the primary action from the toolbar, then copy or download the result. Use Load example when the page offers it, or URL prefill (?q= / ?qb=) so agents and tickets open the same input.

28 is perfect (divisors sum to 28).

Nearby workflows on Toolcore

  • Abundant number checker — See if a number is abundant—proper divisors sum to more than n—computed in-browser. when units or numeric output should be checked on a related calculator.
  • Deficient number checker — Check whether proper divisors sum to less than n—most primes and powers of two are deficient. when units or numeric output should be checked on a related calculator.
  • Prime factorization — Factor whole numbers into prime products—BigInt trial division in your browser, no upload. when units or numeric output should be checked on a related calculator.
  • GCD & LCM calculator — Greatest common divisor and least common multiple for two non-negative integers—BigInt, local only. when units or numeric output should be checked on a related calculator.

Common use cases

  • Demonstrate divisor sums in intro number theory.
  • Sanity-check OEIS perfect entries under 10 million.

Common mistakes to avoid

  • Including n in the divisor sum

    Proper divisors exclude n itself.

FAQ

How high can I test?

Trial division slows on large n; very big values may freeze the tab.

More tools

Related utilities you can open in another tab—mostly client-side.