I talked to 1,000 of the world's top CEOs—here's the No. 1 question they want you to ask at a job interview

As the host of the radio program the "The CEO Show" for the last 15 years, I've interviewed more than 1,000 of the world's top CEOs.

These leaders all come from different backgrounds, from Marriott to McDonald's to Marvel. But all agreed on the No. 1 question a candidate should ask at a job interview: "What traits will help me succeed long-term at the company?"

Employers are moved and impressed by people who are proactive and who get straight to the point, so this is a great first question to ask. I also love how surprisingly simple it is.

Based on my conversations, here are five traits that employers value the most:

1. You keep your promises.

"People rarely do what they say they'll do," one CEO told me. "So when I meet someone who actually does, I know I can trust them."

This means if you say you'll call at 3 p.m., don't call at 3:02. If you say you'll send your resume on Tuesday, don't do it Wednesday morning.

2. You are a lifelong learner.

From a hiring standpoint, lifelong learners are the best investment, because they will continue to add more value with every new thing that they absorb and explore.

They might take extra courses, attend more seminars, read a lot, seek out mentors, or take on new assignments.

3. You do your research.

Never go into a job interview without looking through the company website and the hiring manager's bio. CEOs love it when someone asks them a question about themselves or their career.

One of the fastest ways to be knocked out of the running is to know nothing about the interviewer or the business.

4. You go outside of your comfort zone.

Instead of just doing the bare minimum, do something new and challenging. This is the only way to grow fast.

One way to start is to take on assignments that nobody has volunteered for. As a leader, I always take note of people who do this; it shows initiative and fearlessness.

5. You are constantly curious.

The job interview is your chance to show off your curiosity and thinking skills. My general rule is to always have at least three questions handy.

According to the CEOs I talked to, here are just a few that instantly impressed them:

• "Will I have opportunity to work on the most urgent assignments that others may not want?"
  -Virgil R. Miller, President, Aflac U.S.
• "Was there a time when you received developmental feedback that you disagreed with? How did you handle it?"
  -Sharon Marcil, Chair of North America, Boston Consulting Group
• "Assuming that I am an over-performer, where might I fit in at the company in the long-term?"
  -Adam von Gootkin, Founder and CEO, Highclere Castle Spirits
• "What is the most important thing you would want me to accomplish after one year of working here?"
  -Dennis Devine, President and CEO, Alliant
• "How would I collaborate with more experienced team members?" 
  -Dr. Joseph G. Cacchione, CEO, Jefferson Health
• "What is the hardest thing about being the CEO at your company right now?"
  -Esi Seng, CEO, Tate's Bakeshop 

Robert Reiss is the founder and CEO of the CEO Forum Group, and the host of "The CEO Show."

Don't miss:

• I was VP at Google for 10 years. Here’s the No. 1 skill I looked for at job interviews—very few people had it
• I talked to 1,000 CEOs of highly successful companies—and they all agree this is the No. 1 type of employee
• A neuroscientist shares the 4 'highly coveted' skills that set introverts apart: 'Their brains work differently'

Want to be smarter and more successful with your money, work & life? Sign up for our new newsletter here

Get CNBC's free report, 11 Ways to Tell if We're in a Recession, where Kelly Evans reviews the top indicators that a recession is coming or has already begun.