#[Japt](https://github.com/ETHproductions/japt/), <s>13</s> <s>12</s> 11 bytes

<pre><code>
sw
*V/yU ²</code></pre>

[Try it](https://ethproductions.github.io/japt/?v=1.4.5&code=CnN3CipWL3lVILI=&input=MTIzNA==)

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##Explanation
Implicit input of integer `U`. The empty line at the beginning, prevents the following line from overwriting `U`

    sw

Convert `U` to a string (`s`), reverse it (`w`), convert back to an integer and assign to variable `V`.

    *V

Multiply `U` by `V`.

    /

Divide.

    yU

GCD of `V` and `U`.

    ²

Squared. Implicit output of resulting integer.

---
##Alternative, 13 bytes
Just because I like being able to use `N`.

    NpUsw)mxNry)×

[Try it](https://ethproductions.github.io/japt/?v=1.4.5&code=TnBVc3cpbXpOcnkp1w==&input=MjA4)