I think what you want is:
bash-3.2$ echo "potato" &>2
bash-3.2$
From the man
page for bash:
Redirecting Standard Output and Standard Error
Bash allows both the standard output (file descriptor 1) and
the standard error output (file descriptor 2) to be redirected to the file
whose name is the expansion of word with this construct.
There are two formats for redirecting standard output and standard error:
&>word
and
>&word
Of the two forms, the first is preferred. This is semantically equivalent to
>word 2>&1
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