Black hole number 123

This is about the number 123 ,which acts like a black hole.
Take any natural number which can be regarded as a string such as  9288759..Count the number of even digits,the number of odd digits and the total number of digits.These are 3(evens),4(odds) and 7(total number of digits).Use these three to form the next number or string viz 347.Repeat the process with 347 to get 1,2 and 3 to get the next number/string as 123.Repeat the process again ,you will get the same number 123.There is thus no escape from this number.
You can start with any other number  and in every case the process when continued as many times as are required will end up with 123.
Example-65498299877543---Evens(6),Odds(8),Total (14)
Next number is thus 6814.....Evens(3),Odds(1),Total(4)
Next number 314.....Evens(1),Odds(2),Total (3)...leading to the black hole number 123.