Please, how would I say the number: 11111111111. (eleven ones)
Thank you for your time and if applicable, help.
eleven billion, one hundred and eleven million, one hundred and eleven thousand and one hundred and eleven
two thousands and forty seven 
(there are 10 different sorts of persons: those who get it and those who don’t 
)
Thank you very much, both for the information and the humour.
Ha. I’m glad that I understand this. My friend taught me that form a while ago. 
I like your form, “eleven ones,” the best. It is entirely descriptive and probably the easiest to say. It also includes any and all base(n) representations.
If your name is Bilbo Baggins, you would call it “eleventy-one”.
(for the lesser nerds out there, this is in reference to the party at the beginning of the movie and near the beginning of the book. It’s his 111th birthday, which he also refers to as his “eleventy-first”.
Alternatively, and to be annoying, call it “One one one one one one one one one one one”. Or just put commas to the left of every three ones, and let the reader figure it out. 
For the American version of the answer provided by jamesande, I think it would be the same but without the last “and”.
In the UK, pedants like myself would say “eleven thousand million, one hundred and eleven million, one hundred and eleven thousand, one hundred and eleven.”
1 billion (UK) is 1,000,000,000,000 (1 followed by 12 zeros), 1 trillion = 1 followed by 18 zeros.
In the UK 1,000,000,000 is technically a “milliard”, or a “thousand million”
Unfortunately we’ve lost the linguistic battle with our former colony on this. Maybe we Brits can handle bigger numbers in our head more easily…
Jerry
(1 << 11) - 1
This confuses me. The closest I can come to what I believe you mean is the base 2 representation:
2^11-1,
(two to the eleventh minus one) which is essentially what wobbling bear suggested. Maybe there’s something I’m unaware of here.
It’s C syntax.
(1 << 11): Take a 1 and shift left 11 bits, the result:
100000000000
-1 : Flip it
011111111111
It’s what I do to create bit masks when I program microcontrollers.
Cool. Thanks.
I still think tobbogonist’s description, “eleven ones,” is the most compact and descriptive.
Big 1’s
It’s a uni train with eleven riders
Is it sad that those were the first words that popped into my head after reading OP?
In American English, we are taught not to say the ‘and’.
How the movie One Hundred and One Dalmatians ever got made is beyond me, unless it represents two distinct quantities of Dalmatians.
Greg – by the way, software developers often refer to the concept of internationalization as i18n.
Elf miljard honderdelf miljoen honderdelf duizend honderdelf. Oh well, that’s how I would say it.
Off the top of my head, I would pronounce it 21649 times 513239
edit: Hi, Klaas! Nice to see you here!
I am also here to say hello to Klaas.
Also, good discussion!
One point repetend one, times ten to the power of ten
minus zero point repetend one
But I had to look up “repetend”,
so it would have been a bit more lengthy with me trying to explain what I mean.