Web security firm McAfee also said 15 percent of people surveyed reported they save password information to apps and websites they use on their phones and more than half who do have and use passwords said they've shared them with others, CNN reported Tuesday.
"The unfortunate reality is that everyone loses things, and our devices can get stolen," Robert Siciliano, an identity-theft specialist at McAfee, wrote in blog post. "And when that happens to your smartphone or tablet, it can be devastating."
Women are slightly less likely than men to password-protect their phones, McAfee said; 54 percent of those surveyed who said they don't were women.
"Many of us use upwards of 10 apps on our devices during a typical week," Siciliano wrote. "The majority of these apps are logged into our most critical accounts including e-mail, text, banking, social media, payment apps and others that are linked to our credit cards.
"And because mobile app developers know that we are more apt to use their programs if they are easy to access and convenient to use, a lot of apps are programmed to automatically keep you logged in for days, weeks, months or until you manually revoke access."
Siciliano recommended users password-protect all their devices and refrain from recording or sharing the passwords.