even perfect numbers

GPTKB entity

Statements (27)
Predicate Object
gptkbp:instanceOf gptkb:mathematical_concept
gptkbp:all_known_perfect_numbers are even
gptkbp:defines A perfect number that is even
gptkbp:discoveredBy gptkb:Euclid
gptkbp:example 6
gptkbp:form 2^(p-1) × (2^p − 1) where 2^p − 1 is prime
gptkbp:fourth_example 8128
https://www.w3.org/2000/01/rdf-schema#label even perfect numbers
gptkbp:property triangular number
the sum of the reciprocals of the divisors equals 2
abundant number
ends with 6 or 28 alternately
equal to the sum of their proper divisors
harmonic divisor number
if 2^p − 1 is prime, then p is also prime
number of divisors is a power of 2
all even perfect numbers are congruent to 6 mod 12 except 6
related to binary representations
the largest known perfect numbers are even
gptkbp:relatedTo gptkb:Mersenne_primes
gptkbp:second_example 28
gptkbp:sequence 6, 28, 496, 8128, 33550336, ...
gptkbp:studiedBy gptkb:Euler
gptkbp:third_example 496
gptkbp:unknown_property existence of odd perfect numbers is unknown
gptkbp:bfsParent gptkb:Euclid–Euler_theorem
gptkbp:bfsLayer 8