Prime Minister Najib Abdul Razak said his first impression of Facebook founder and one of the world’s richest individuals Mark Zuckerberg is that he did not appear intelligent.

On the contrary, he added that Zuckerberg is actually "super smart".

"My initial reaction, he doesn't look very smart.

"But actually he is very smart. He is super smart but doesn't look very smart," he joked during a question and answer session with Catcha Group CEO Patrick Grove at the Wild Digital Conference in Le Meridian Kuala Lumpur.

The prime minister also said he visited Zuckerberg's office at the Silicon Valley when he was on a working trip to the United States, and shared his thoughts on the work culture there.

"The whole atmosphere is very informal, Zuckerberg...So informal,” he added.

Najib said he was attracted by the manner in which Facebook employees carried out their work in a laidback fashion and without hierarchy.

“I like their attitude... They work in their own way, while munching on muffins, drinking Starbucks coffee and coming up with ideas.

“It is a different world,” he added.

Najib met Zuckerberg in 2013 at Facebook’s head office in Menlo Park, and the two held a private meeting.

The pair was said to have discussed potential collaborative efforts between Facebook and Malaysia.

During his visit, Najib also visited another social media giant, Google, at its headquarters in Mountain View, not far from San Francisco city.

The prime minister was given a tour around the complex and had a meeting with senior officials of Google.