
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
A natural number greater than 0, if it satisfies the condition that the sum of all its factors equals twice itself, is called a perfect number. For example, 6 has all its factors as $1, 2, 3, 6$ and $1 + 2 + 3 + 6 = 12$. Thus, 6 is the smallest perfect number. Whether there are infinitely many perfect numbers is still one of the great unsolved problems in mathematics. The study of perfect numbers can begin by calculating the sum of all factors of a natural number. The sum of all factors of 81 is $\qquad$.

Present the answer in LaTex format: \boxed{Your answer}
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