While many millennials feel as if they don't have enough money to do what they want, many say their jobs are about more than a paycheck.

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According to a recent Gallup poll, 69 percent of millennials said they have enough money to buy what they need, but only 38 percent said they have enough to buy things they want.

But half are confident that the U.S. economy is "getting better." Other generations are less optimistic.

Money isn't the most important thing for working millennials. They also want good managers, jobs they're interested in and opportunities to grow. Flexible work hours and fulfilling a sense of purpose are also important to this group.

Regardless, half said they would consider taking a job with a different company for a 20 percent raise or less.

The key to keeping millennials on the job might be finding what engages them most at work. Gallup found that those who said they felt engaged at work were 26 percent less likely to leave for a raise.

By 2020, 86 million millennials -- or 40 percent of the total working population -- will be in the workplace, Jamie Gutfreund, chief strategy officer for the Intelligence Group told Forbes in a 2014 interview.