As President Obama prepares to hand over the White House to President-elect Donald Trump, Mr. Obama spoke Sunday about his successor, his campaign and the challenges he’ll face in office -- and said people shouldn’t underestimate the GOP businessman who upended the political world with his victory in November.

“First of all -- I think everybody has to acknowledge don’t underestimate the guy, because he -- he’s going to be 45th president of the United States,” Mr. Obama told “60 Minutes” in the last network interview of his presidency.

Mr. Obama acknowledged that this transition period has been one of the stranger ones in recent political history.

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“It’s unusual. I’ll agree with that,” he said. “I suspect the president-elect would agree with that.”

He said Mr. Trump’s rise to power has coincided with an era in which the way people get their information is changing -- a reference to Mr. Trump’s frequent Twitter habit. That ability for a president to quickly and directly reach the people comes with both “power” and “danger,” he said.

“We are moving into an era where a lot of people get their information through tweets and sound bites and some headline that comes over their phone,” he said. “And -- I think that -- there’s a power in that. There’s also a danger: what generates a headline or stirs up a controversy and gets attention isn’t the same as the process required to actually solve the problem.”

He warned Mr. Trump over his sustained criticism of the intelligence community, saying there’s a need for trust between a president and the intelligence agencies he relies on for information.

“You’re not going to be able to make good decisions without building some relationship of trust between yourself and that community,” he said.

(Asked whether he saw that happening, Mr. Obama replied: “Not yet, but … he hasn’t gotten sworn into office yet.”)

Additionally, Mr. Obama cautioned Mr. Trump against upending too many of the the presidency’s “institutional traditions,” which he said are traditions for a reason.

“The one thing I’ve said to him directly, and I -- I would advise -- my Republican friends in Congress and supporters around the country, is just make sure that-- as we go forward certain norms, certain-- institutional traditions don’t get eroded,” he said. “Because there’s a reason they’re in place.”

Mr. Obama acknowledged Mr. Trump was a “change candidate,” albeit in a very different way than he himself was during the 2008 campaign. He also said Mr. Trump was an “unconventional” candidate who ran an “improvisational campaign.”

Asked, however, whether he thinks it’s possible to run an “improvisational presidency,” Mr. Obama replied: “I don’t think so.”

“He clearly was able to tap into a lot of grievances,” Mr. Obama said. “And he has a talent for making a connection with his supporters that overrode some of the traditional benchmarks of how you’d run a campaign or conduct yourself as a presidential candidate.”