First Number to Contain Each Letter
JavaScript (Node.js),  78 75 74  73 bytes

c=&gt;(n=([x]=Buffer(c+'8&gt;P7 $(#%  +;! MD &amp;&quot;$%&quot;&amp;4 '))[x-96]-53)&lt;0?n+21:10**n

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How?
Each value is encoded with a single printable character. We use the ASCII range \$[32..52]\$ to encode \$n-32\$ and the range \$[53..80]\$ to encode \$10^{n-53}\$.
Commented
c =&gt;                                   // c = input character
  ( n =                                //
    ( [x] =                            // let x be the 1st byte of the
        Buffer(                        // buffer made of:
          c +                          //   c followed by
          '8&gt;P7 $(#%  +;! MD &amp;&quot;$%&quot;&amp;4 ' //   the encoded values
        )                              //
    )[x - 96]                          // let n be the encoded value corresponding to c
    - 53                               // minus 53
  ) &lt; 0 ?                              // if n is negative:
    n + 21                             //   return n + 21
  :                                    // else:
    10 ** n                            //   return 10 ** n