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IMS
2008 IMS
8
8
Part of
2008 IMS
Problems
(1)
Find all numbers
Source: IMS 2008
5/10/2008
Find all natural numbers such that
n
σ
(
n
)
≡
2
(
m
o
d
ϕ
(
n
)
)
n\sigma(n)\equiv 2\pmod {\phi( n)}
nσ
(
n
)
≡
2
(
mod
ϕ
(
n
))
modular arithmetic
number theory proposed
number theory