Any method or procedure that converts any word or group of letters into a unique integer.
Given the method and the integer, one can figure out the word. Not all integers correspond to a word.
A specific procedure might work only with a specific alphabet, but with slight modification could be made to work with another alphabet.
To decipher this message, you need to figure out what WORD2NUM procedure I used.
First here is a partial "Rosetta Stone".
ALL = 13737
YOUR = 1618515
ARE = 13946
BELONG = 689654284
TO = 1068
US = 1108
WHAT = 1515413
YOU = 44958
SAY = 36682
MAIN = 1040063
SCREEN = 1714486703
TURN = 1392899
ON = 887
Here is the ciphertext:
831805 21303239 48023009 48023009 1235714990931 17741 16438 48023009 23842631010 48023009 370 1086220895 52925280 17741 13993 891 926381 1008910850 13737 1618515 527198 13946 689654284 1068 1108 38112134