Multiplicatively perfect numbers: Difference between revisions
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{{draft task}}
=Duplicate of task [[Semiprime]]=▼
If the product of the divisors of an integer n (including n itself) is equal to n^2, then n is a ''multiplicatively perfect number''.
Equivalently: the product of the proper divisors of n (
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;Task
Find and show on this page the multiplicatively perfect numbers below '''500'''.
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;Stretch
Find and show the number of multiplicatively perfect numbers under '''500''', '''5,000''', '''50,000''' and '''500,000''' and for each of these limits deduce (avoid counting separately) and show the number of ''semi-primes'' (numbers which are the product of exactly two primes) under that limit.
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;Related (and near duplicate) task
;See also:
* The OEIS sequence: [[oeis:A007422|A007422: Multiplicatively perfect numbers]]
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