Ambiguous Length Varbinary Variable

Hi,

I'm trying simple code:

declare @varbinary varbinary(8000)
set @varbinary = 2592
print len( @varbinary )

number length
2590 4 bytes
2591 4 bytes
2592 3 bytes ????
2593 4 bytes

All number in range 1 - 9000 has length 4 bytes except these numbers:

32,288,544,800,1056,1312,1568,1824,2080,2336,2592,2848,3104,3360,3616,3872,4128,4384,4640,4896,5152,5408,5664,5920,6176,6432,6688,6944,7200,7456,7712,7968,8480,8736,8992

These numbers has length 3 bytes !

Why?

I´m using varbinary variable to transport ID values and parsing in loop

set @cnt = len( @binEmpIDList ) / 4 -- 4 length
....
insert into @List( ID ) values( substring( @varbinary, @i * 4 + 1, 4 ) )
...

but this algorithm malfunctioning in enumerated numbers.

Please help, how correct this.
ID values in @varbinary too much. I cannot using convert varbinary to bigint and convert bigint to string.


Dalibor