Only Number which is Sum of 3 Factors is 6/Mistake

Source Work

 * The Dictionary
 * $6$
 * $6$


 * The Dictionary
 * $6$
 * $6$

Mistake

 * It is the only number that is the sum of exactly $3$ of its factors, ...

Correction
The statement should be:
 * It is the only number that is the sum of exactly $3$ of its distinct coprime factors, ...

Let $n$ be such a positive integer with corresponding divisors $a, b, c$ such that:
 * $a + b + c = n$

We note that the set $\set {k a, k b, k c}$ satisfy the same properties trivially as divisors of $k n$.

Hence it is necessary definitely to require the set to be coprime.

Also note the trivial observation that $1 + 1 + 1 = 3$, which explains the need to specify that the factors be distinct.