function number2Chinese($num, $m = 1) {

	switch($m) {

		case 0:

			$CNum = array(

				array('零','壹','贰','叁','肆','伍','陆','柒','捌','玖'),

				array('','拾','佰','仟'),

				array('','萬','億','萬億')

			);

		break;

		default:

			$CNum = array(

				array('零','一','二','三','四','五','六','七','八','九'),

				array('','十','百','千'),

				array('','万','亿','万亿')

			);

		break;

	}

	if (!is_numeric($num)) {

		return false;

	}

	$flt = '';

	if (is_integer($num)) {

		$num = strval($num);

	}else if(is_numeric($num)){

		$num = strval($num);

		$rs = explode('.',$num,2);

		$num = $rs[0];

		$flt = $rs[1];

	}

	$len = strlen($num);

	$num = strrev($num);

	$chinese = '';

	for($i = 0,$k=0;$i < $len; $i+=4,$k++){

		$tmp_str = '';

		$str = strrev(substr($num , $i,4));

		$str = str_pad($str,4,'0',STR_PAD_LEFT);

		for ($j = 0; $j < 4; $j++) {

			if($str{$j} !== '0'){

				$tmp_str .= $CNum[0][$str{$j}] . $CNum[1][4-1-$j];

			}

		}

		$tmp_str .= $CNum[2][$k];

		$chinese = $tmp_str . $chinese;

		unset($str);

	}

	if($flt !== ''){

		$str = '';

		for ($i=0; $i < strlen($flt); $i++) {

			$str .= $CNum[0][$flt{$i}];

		}

		$chinese .= "点{$str}";

	}

	return $chinese;

}

$str = number2Chinese(123458656.789);

var_dump($str);

运行结果

string(63) "一亿二千三百四十五万八千六百五十六点七八九"