List of integer factorization into n terms
Because Divisor is quite efficient at its job, the only optimization I see, is to avoid unnecessary calls to it, by using memoization technique:

FactorIntoFixedTerms[in_Integer, terms_Integer] := Block[{f, div},
  div[n_] := (div[n] = Divisors[n]);
  f[n_, 1] := {{n}}; 
  f[n_, k_] := 
   Join @@ Table[{q, ##} &amp; @@@ 
      Select[f[n/q, 
        k - 1], #[[1]] &gt;= 
         q &amp;], {q, #[[2 ;; \[LeftCeiling]Length@#/
             k\[RightCeiling]]] &amp;@div@n}];
  f[in, terms]
  ]


This can lead to substantial timing reduction:

In[683]:= FactorIntoFixedTerms[1453522322112240, 6] // Length // Timing

Out[683]= {0.047, 47}

In[685]:= foriginal[1453522322112240, 6] // Length // Timing

Out[685]= {0.39, 47}