PostgreSQL displaying integer inserted without commas, with commas (formatted like currency or similar)

Question

SQL Server guy, new to PostgreSQL. Created the below table, performed the below insert, then ran a SELECT to see the data, yet the row shows the integer formatted with columns to break up the integer. Is this just a formatting style in the HeidiSQL utility I'm using, or is the data actually being stored as x,xxx,xxx,xxx rather than xxxxxxxxxx.

Table:

CREATE TABLE customer (
    business_partner_id INTEGER PRIMARY KEY,
    first_name VARCHAR(100),
    last_name VARCHAR(100),
    organisation_name VARCHAR(200),
    date_of_bith DATE,
    gender VARCHAR(50),
    customer_type VARCHAR(50),
    store_joined VARCHAR(10),
    store_joined_date DATE,
    created_date_time TIMESTAMP,
    updated_date_time TIMESTAMP);

Insert:

-- Insert a customer 
INSERT INTO customer VALUES 
(1029884766,'James','Matson','Unknown','1980-02-17','M','Standard','303',CURRENT_DATE,CURRENT_TIMESTAMP,CURRENT_TIMESTAMP)

Query results: