Stuck - Sort In Group By

Question

I am trying to sort a grouped tbl_df data table.

I group by productId

   data %>%
    group_by(productId) %>%
    summarize(Totals = sum(amount, na.rm = TRUE),
              count = n())

That's my summary, this looks all good.

        # A tibble: 84 x 3
       productId     Totals count
           <dbl>      <dbl> <int>
     1        16     50000      1
     2        26 104770730.   464
     3        80   2315000     11
     4       100 138487667    444
     5       105  41225000     83
     6       106   5365000     21
     7       126   9762950     43
     8       127   7950000     36
     9       213    900000      5
    10       218    200000      2

Now, I would like to sort by Totals - the summary I created, descending. Or sort by count.

How do I do that? I tried mutate and I tried,

    data %>%
        group_by(productId) %>%
        summarize(Totals = sum(amount, na.rm = TRUE),
                  sort(Totals, decreasing = TRUE),
                  count = n())

This only gives me a duplicated Totals, column.

# A tibble: 84 x 4
   productId     Totals `sort(Totals, decreasing = TRUE)` count
       <dbl>      <dbl>                             <dbl> <int>
 1        16     50000                             50000      1
 2        26 104770730.                        104770730.   464
 3        80   2315000                           2315000     11
 4       100 138487667                         138487667    444
 5       105  41225000                          41225000     83
 6       106   5365000                           5365000     21
 7       126   9762950                           9762950     43
 8       127   7950000                           7950000     36
 9       213    900000                            900000      5
10       218    200000                            200000      2
# … with 74 more rows

Any thoughts? Thank you very much.