from decimal import Decimal


def format_number(number):
    number = Decimal(str(number))
    integer_part = number // 1
    fractional_part = number - integer_part

    formatted_integer = "{:,.0f}".format(integer_part).replace(",", " ")

    if fractional_part == 0:
        return formatted_integer

    fractional_str = f"{fractional_part:.30f}".split(".")[1]
    first_non_zero = next(
        (i for i, char in enumerate(fractional_str) if char != "0"), len(fractional_str)
    )
    result_fractional = fractional_str[: first_non_zero + 3]
    result_fractional = result_fractional.rstrip("0")

    if not result_fractional:
        return formatted_integer

    return f"{formatted_integer}.{result_fractional}"