One million dollars. Wouldn’t it be nice to retire with that pile of cash?

Millennials, Gen Xers and Boomers think so, based on a recent survey from TD Ameritrade.

About six in 10 of 1,000 adults surveyed (23 and up with at least $10,000 in investable assets) said yes to this statement: “When I retire, $1 million will be enough for a comfortable retirement.”

“One million dollars is a round number, but for so many, it seems like an unimaginably large number,” said Keith Denerstein, director of investment products and guidance at TD Ameritrade.

A magic number like $1 million is a good conversation starter, said AJ Smith, VP of content and financial education at SmartAsset, which has a website where you can look for a financial planner and explore tools and calculators.

“Motivation is personal. Looking at a number helps you get going to save,” but thinking about smaller numbers may provide a more realistic approach, Smith said.

Start saving $5 a week, she said, then $10 and $100 or more. If you have a 401(k), try to do better than just 3%, upping it to 10% or 15%.

There is another option to try to reach $1 million faster: Become a super saver.

A recent Principal Financial Group survey describes “a pocket of younger Americans” who “are saving big for their futures.”

Gen X and Gen Y super savers make some sacrifices such as driving an older car, owning a modest home, not traveling as much as they’d like, and embracing DIY projects, Principal noted.