The fact that you have rows with an identical id of 2141750 verifies a
corrupted primary index.
To correct it, you need to decide which row to keep.
So review the results of
SELECT * FROM some_table WHERE ctid = (79664,59) OR ctid = (79772,23)
DELETE FROM some_table
WHERE id = 2147150
AND field1 = {value for field1 of row to delete}
AND field2 = {value for field2 of row to delete}
...
...
AND fieldn = {value for fieldn of row to delete};
Then
REINDEX TABLE some_table;