
> 
> "Adleman refers to integers which factor completely into small primes as “smooth” numbers." (ME Hellman, JM Reyneri. *Advances in Cryptology*, 1983: [citation link](http://scholar.google.com/scholar?q=%22Adleman%20refers%20to%20integers%20which%20factor%20completely%20into%20small%20primes%20as%20smooth%20numbers.%22).)
> 
> 
> 


Does anyone know what is the intuitive reason behind the choice of the adjective
"smooth" for this concept?



Why are smooth numbers called "smooth"?
I asked Ron Rivest, and he replied:



> 
> Yes, I coined the term "smooth number" to refer to a number that
>  has only small prime factors.  I don't recall now much about the 
>  thinking process, except that smooth is rather the opposite of
>  "lumpy"...
> 
> 
> 


