Barbara Corcoran has spent eight seasons on "Shark Tank," which airs Fridays at 9 p.m. on ABC. ABC/John Fleenor "Shark Tank" investor Barbara Corcoran knows Donald Trump better than most people. They both built their real estate fortunes around the same time in New York City.

"I grew up with him," Corcoran told Business Insider during a "Shark Tank" event at New York's Paley Center for Media this week.

In the early 1970s, both Corcoran and Trump were starting their real estate careers.

Corcoran co-founded a real estate business called The Corcoran Group with a $1,000 loan from her then-boyfriend and co-founder. She then later started The Corcoran Report, which followed NYC's real estate trends. At around the same time, Trump took control of his father's real estate and construction business, which he later named The Trump Organization.

When it comes to business, Corcoran clearly respects the Republican presidential candidate.

"From the day I met Donald, I remember my first thought on him was that I've never met a better salesman in my life," she recalled. "I was in more business meetings where a customer, client, and even a walk-by had no interest in what he was wanting to sell. And by the time five minutes of Donald talking was over, the guy was begging him for the deal."

"I probably learned so much about chutzpah and salesmanship watching him, which I tried to incorporate but never really pulled it out," she continued. "I'm a medium salesman. He's an amazing salesman. And what we see in the presidential election today is a phenomenal salesman selling the American people."

Trump has been criticized by many, including Corcoran's "Shark Tank" colleague Chris Sacca, for building his business with help from his rich father, but she doesn't believe that's fair.

"As a businessman, [Trump is] clever as a fox and built his empire with a little help from his dad," she told us. "But most of the credit is due him."

And yet with more than three decades of knowing Trump, Corcoran can't support his bid for president. She finds him too divisive a person for the job.

"As a leader, I couldn't imagine anyone who would be a less effective leader," she said. "I think leadership has everything to do with integrity. I think it has to do with teaching people to aspire. I think at the core of leadership, you have to get everyone on the same team to move the ball ahead. And you can't have discord, you're a peacemaker as a leader if you want to have a community of spirits and hearts. And I think in all those categories, he has to come back as a different person. Next life, maybe."