Support Numberphile... collect a nice memento... baffle your local postal workers?

This postcard features the number 89's "reverse add" sequence until it reaches palindrome glory.

This unusually long process is the lengthiest of any number under 100. It takes 24 iterations.

The whole tedious procedure is shown on the postcard.

The back features the card's unique number (between 1 and 89) and the signature of Numberphile creator Brady Haran (which may slightly lessen its value).

Hand-signed and numbered by Brady (who also did the boring calculations) 

PLEASE NOTE:

This postcard will be sent through the mail, NOT in an envelope.

It will endure the rigours of normal 'snail mail'.

This is deliberate so the postcard will receive postal 'cancellation stamps' --- and also be enjoyed by all who sort and deliver it!

The earliest orders will receive lower edition numbers.

Please note pricing is in UK Pounds, not dollars.

Postage is included to all countries.