Psy’s Gangnam Style video has long been the most watched clip on YouTube. Now it’s forced a rethink of the site’s “hit counter.”

The video recently passed the 2,147,483,647-view mark. Maths and computing geeks among us may already have spotted the significance of that, but for the rest of us, it’s all down to that fact that YouTube was set up to use one of the most common integer formats in computing.

That figure of just over two billion is the longest that can be expressed as a single number using a 32-bit signed integer. YouTube says it never expected a video would reach such a view count, so only now has had to rethink its coding.

It’s not said if it has rolled out the new counting display across all videos. For the moment the Gangnam Style video counter is set up to appear stuck at 2,147,483,647 but hovering over the counter triggers an animation that eventually reveals the current total.

While some have speculated that YouTube has switched to a 64-bit integer format, that may not be the case. A signed integer, as is currently used on YouTube, is one that includes a notification of whether the number is positive or negative. As that’s clearly not an issue when counting video views, it’s possible YouTube has switched to using a 32-bit unsigned integer, which would allow up to 4,294,967,295 views before causing problems.

What the number means for Psy and company is also a mystery as the royalty rates on offer to record companies for music video views are covered by non-disclosure agreements and are believed to vary from company to company. Based on figures that have been published by one song’s co-writer ($38.49 as a 50 percent share on royalties for 2,118,000 plays), YouTube will have paid out just over $78,000 for Gangnam Style.

The limits of the signed 32-bit integer aren’t just an issue for measuring catchy tunes. Unix systems that use it for tracking time will hit their limit on January 19th, 2038 and then “reset” to December 1901, a problem colloquially known as the Unix Millennium Bug.