Counting the same summs is very easy, just use COUNTIF() like as

```
=COUNTIF(<range of row>;<Sum>)
```

For example `=COUNTIF($A$1:$GR$1;841)`

or simple `=COUNTIF(1:1;841)`

will count cells iin first row with value 841

Search columns with identical sums a bit more complicated and requires more complex formula. For example, it might be a formula similar to this

```
{=IFERROR(TEXTJOIN(",";1;IF(1:1=841;SUBSTITUTE(ADDRESS(1;COLUMN(1:1);4);"1";"");""));"")}
```

This formula show the column names separated by commas, where the first line contains the sum of 841. Or leave the cell empty if there is no value in any of the cells.

**Important!** Notice the braces in which the formula is enclosed! This means that this is an array formula and must be entered in a special way - the formula should be entered by pressing the key combination **Ctrl + Shift + Enter** or do as in this image

*Please not create new answer like as "Thx it work"!*