Some numbers are just numbers. Others become part of cultural history. For us, 73 will always be synonymous with FAC 73, the catalogue number assigned by Factory Records to New Order's Blue Monday, one of the most influential records ever made and the inspiration behind our name and our core brand colours.

One of the most fascinating details surrounding New Order's iconic Blue Monday is that its famous sleeve design wasn't just visually striking, it was also coded. Designed by graphic designer Peter Saville, the artwork uses a colour-coded system inspired by computer punch cards and floppy disks.

Each coloured segment corresponds to a letter or number, creating a hidden message that reveals the artist, title and catalogue number of the record. At a time when album artwork was often little more than packaging, Saville transformed the sleeve into a puzzle, inviting fans to decode it themselves. The result became one of the most celebrated examples of graphic design in music history, perfectly capturing the spirit of innovation, mystery and experimentation that defined Factory Records.

 = FAC73 15YEARS

Here are some other stories, coincidences and curious facts that make the number 73 more interesting than you might think.

73 is the 21st prime number.

But here's the fun bit:

• Reverse it and you get 37
• 37 is the 12th prime number

So:

73 = 21st prime
37 = 12th prime

The positions reverse as well.

And it gets even stranger:

• Reverse 21 and you get 12.
• Reverse 73 and you get 37.

It's one of the most famous numerical curiosities in mathematics.