Whenever I need an arbitrary const int I use 1729. I've left a trail of 1729s in the codebases I've touched over the years, and I like the thought of other hackers recognising the number when they have to fix the bugs I've left behind.
I read a commentary on Ramanujan when I was about 14 in the four volume set "The World of Mathematics". The quotes by the famous mathematician G.H. Hardy, Ramanujan's mentor, are apropos:
"I had ridden in taxi-cab No 1729, and remarked that the number
seemed to me rather a dull one, and that I hoped it was not an
unfavourable omen. 'No,' he replied, 'it is a very interesting
number; it is the smallest number expressible as a sum of two
cubes in two different ways.' ... 'His powers of calculation,
were very unusual, but they could not reasonably be called
'abnormal.' ...
"It was his insight into algebraical formulae, transformations
infinite series, and so forth, that were the most amazing. On
this side most certainly I have never met his equal, and I can
compare him only with Euler or Jacobi. ...