Dirk Nowitzki, who presented the jersey to the president, said he heard Obama was "a big, big fan of Michael Jordan," who wore the number. Jordan, now the majority owner of the Charlotte Bobcats, won six championships in Chicago, Obama's hometown.
"Thank you so -- well, you know, I was actually -- I was 23 before Jordan," Obama said.
"Oh, you were?" Nowitzki replied.
"I was," Obama responded to laughter. "So he got the number from me, I think. He stole it."
The president complimented Mavericks owner Mark Cuban for his "outstanding group of players and coaches."
He said the Mavericks, coached by Rick Carlisle, "have a heart that's the size of Texas" and won their title "because they know how good teams win -- not just by jumping higher or running faster, but by finding the open man, working together, staying mentally tough, being supportive of each other, playing smarter."