A Gödel numbering assigns to each finite word in a finite alphabet a unique natural number. As an example, if A,B,…,Z are counted as 1,2,…,26, then the word NUMBER would be assigned the number 214321513721151318. Using the primes 2,3,5,… in order and as N is the 14th letter, U the 21st, etc. As prime factorization is unique, Gödel numbering is one-to-one. See also halting problem.