One in nine people still use '1234' as their PIN or passwords says a new study.
By contrast, the rarest code of all is '8068', as only 0.000744 percent of people choose this random string of digits as a PIN.
According to the Daily Mail, the staggering data shows that it is possible to guess a PIN in just one go 10 percent of the time.
The analytics firm Data Genetics studied a database of 3.4 million four-digit passwords, drawn together from lists of PINs, which have been leaked by hackers over the past few years.
Although the codes in question are computer passwords, not ATM numbers, it is reasonable to assume that many people use the same PIN for both functions, the report said.
Along with '1234', other extremely popular digits that are used as passwords are '1111' and '0000'.
According to the report, other frequently used PINs are not patterns, but are memorable in other ways - for example, many people seem to use the year they were born.
When it comes to the least popular numbers, Data Genetics found codes with little significance such as '9629' and '6835'.
The rarest PIN of all, '8068', was seen just 25 times in the 3.4 million codes studied.
However, Data Genetics warned that now that number's rarity is public knowledge, it might not be the best idea to use it for security reasons.