Popular numbers used in leaked passwords

Last time we’ve seen some popular fictional passwords, and how they are used in Exploit.in – a collection of 739,861,478 leaked passwords. I wanted to take another look at some popular numbers and how they are used in passwords.


How many digits of Pi have you memorized? I’ve got 6 digits after the decimal: 3.141592. Not bad, but could be better. Let’s see how far the Exploit.in community takes it:
17,713 password have exactly 7 decimal places of Pi (1415926). 1,626 have 10 decimal digits. The record is a single password with 37 digits of Pi – 1415926535 8979323846 2643383279 502884179. The last two digits in that password are cunningly reversed (79 instead of 97), so unfortunately they don’t count.

Here’s a breakdown for the digits of Pi in passwords:

Math constants

Same as with Pi, I’m only considering digits after the decimal point:

Value Digits Passwords
e 7182818284 337
e 71828182845904523536 7
√2 4142135623 114
√3 7320508075 21
Phi 6180339887 86
Euler Mascheroni 5772156649 1

Didn’t make it: Conway’s Constant, Khinchin’s constant, and Glaisher Kinkelin.

Fibonacci sequence

One advantage of the Fibonacci sequence is that if you forget your password you can always calculate it. 25,316 unforgettable passwords contain 8 Fibonacci numbers (1 through 21). Only 4 passwords make it all the way to the 15th number, 610:

Physics and Chemistry constants

Number Digits Passwords
Light Speed Meters/Second 299792458 1988
Light Speed Miles/Second 186282 298
Light Speed Kilometers/Second 299792 2561
Light Speed Miles/Hour 670616629 1
Avogadro 6.02×1023 6021023 259
Avogadro 6.022×1023 60221023 73

Avogadro passwords that make good use of special characters include m602x1023e and 602*1023.

Pop-culture numbers

Unsurprisingly, numbers that appear on TV or song lyrics make their appearance in passwords. I couldn’t find too many examples:


Tommy Tutone 867-5309 / Jenny 8675309 (Exact password) 13894
Tommy Tutone 868-5309 / Jenny 8675310 (contain) 28231
Queens of the Stone Age Regular John 16278263789 7


40,430 passwords are exactly 4815162342. Additional 34,318 password contain 4815162342, and another 1,058 passwords have The Numbers with separators, for example L48O1516S2342T.

See also

For a more serious analysis of password trends and common patterns: