All the numbers below should be assumed to be positive integers.
Definition. An abundant number is an integer n whose divisors add up to more than
In.
Definition. A perfect number is an integer n whose divisors add up to exactly In.
Definition. A deficient number is an integer n whose divisors add up to less than In.
Example. 12 is an abundant number, because 1 + 2 + 3+ 4 + 6+12 = 28 and 28 >
2x12. However, 14 is a deficient number, because 1 + 2 + 7 + 14 = 24, and 24 <
2 x 14.
Your task is to consider the following conjectures and determine, with proofs,
whether they are true or false.
Conjecture 1. A number is abundant if and only if it is a multiple of 6.
Conjecture 2. If n is perfect, then kn is abundant for any k in N.
Conjecture 3. If p1 and p2 are primes, then p1/p2 is abundant.
Conjecture 4. If n is deficient, then every divisor of n is deficient.
Conjecture 5. If n and m are abundant, then n + m is abundant.
Conjecture 6. If n and m are abundant, then nm is abundant.
Conjecture 7. If n is abundant, then n is not of the form pm for some natural m and
prime p.