# [MATL], 7 bytes

    `sYftnq

[Try it online!][TIO-j8cwnwgz]

[MATL]: https://github.com/lmendo/MATL
[TIO-j8cwnwgz]: https://tio.run/##y00syfn/P6E4Mq0kr/D/fyNTAwA "MATL – Try It Online"

###Explanation

    `      % Do...while
      s    %   Sum of array. The first time it implicitly takes the input number, 
           %   and its "sum" is that number. In subsequent iterations it sums the
           %   array of prime factors from the previous iteration
      Yf   %   Array of prime factors
      t    %   Duplicate
      n    %   Length
      q    %   Subtract 1
           % End (implicit). Proceeds with next iteration if the top of the stack
           % is non-zero, that is, if the latest obtained array of prime factors 
           % had more than one entry
           % Display stack (implicit)