perfect number
English
Etymology
Calque of LatinCategory:English terms calqued from Latin#PERFECTNUMBERCategory:English terms derived from Latin#PERFECTNUMBER numerus perfectus, with this use of perfectus itself a semantic loan from Ancient GreekCategory:English terms derived from Ancient Greek#PERFECTNUMBER τέλειος (téleios).
Pronunciation
Noun
perfect number (plural perfect numbers)Category:English lemmas#PERFECTNUMBERCategory:English nouns#PERFECTNUMBERCategory:English countable nouns#PERFECTNUMBERCategory:English multiword terms#PERFECTNUMBERCategory:English entries with incorrect language header#PERFECTNUMBERCategory:Pages with entries#PERFECT%20NUMBERCategory:Pages with 1 entry#PERFECT%20NUMBER
- (number theoryCategory:en:Number theory#PERFECTNUMBER) A number that is the sum of all of its divisors except itself.
- The factors of 6 are 1, 2, 3 and 6, and 1 + 2 + 3 = 6, so 6 is a perfect number.Category:English terms with usage examples#PERFECTNUMBER
- The factors of 28 are 1, 2, 4, 7, 14 and 28, and 1 + 2 + 4 + 7 + 14 = 28, so 28 is a perfect number.Category:English terms with usage examples#PERFECTNUMBER