A well known chemist name from london

Question: A well-known chemist name from London was murdered while his visit to Calcutta(India).

He left a note ” 7916227 ”

A local detective Byomkesh Bakshi was called to solve the case, Chemist five assistant is under suspicion of killing the chemist named :

Austin, Terry, Cole, Hazard, Oscar, and Drogba.

After reading the note, Byomkesh Bakshi instantly asked the police to arrest the murderers.

Who are the murderers?

Answer: The correct answer is Oscar and Austin