php格式化数字为“0.00万”

/**
 * @param $number
 * @return string
 */
function formatNumber($number)
{
    if (empty($number) || !is_numeric($number)) return $number;
    $unit = "";
    if ($number > 10000) {
        $leftNumber = floor($number / 10000);
        $rightNumber = round(($number % 10000) / 10000, 2);
        // $rightNumber = bcmul(($number % 10000) / 10000, '1', 2);
        $number = floatval($leftNumber + $rightNumber);
        $unit = "万";
    } else {
        $decimals = $number > 1 ? 2 : 6;
        $number = (float)number_format($number, $decimals, '.', '');
    }
    return (string)$number . $unit;
}