शङ्कराचार्यं सुखलं बधरां...
śaṅkarācāryaṃ suklāṃ baradharā... (This is a mishearing. The actual third line is:) suklam baradharam lyrics
Śaṅkarācāryaṃ (or Śaṅkaram) Śuklāmbara-dharaṃ (repeating the first phrase) ... The common complete verse dedicated to Shankara is: suklam baradharam lyrics
शुक्लाम्बरधरं विष्णुं शशिवर्णं चतुर्भुजम् | प्रसन्नवदनं ध्यायेत् सर्वविघ्नोपशान्तये || suklam baradharam lyrics
Note: The phrase you mentioned, "suklam baradharam," is a phonetic approximation of "Suklambaradharam." There is no separate "suklam baradharam" lyric; it is the same mantra.
In reality, the well-known mantra for Adi Shankaracharya is: