<?php
$input = "1325644";
$str = str_split($input);
$len = count($str);
for($a=0; $a<$len; $a++){
$jum[]=0;
	for($b=0; $b<$len; $b++){
		if($str[$a] == $str[$b] && similar_text($str[$a], $str[$b])==1){
			$jum[$a]++;
		}
	}
	$ar[] = implode(array($jum[$a], $str[$a]));
}

$arr = array_unique($ar);
for($a=0; $a<count($arr); $a++){
	echo "karakter ".$arr[$a][1]." ada ".$arr[$a][0]." huruf\n";
}
?>
-------
$input = "1325644"
output = 
karakter 1 ada 1 huruf
karakter 3 ada 1 huruf
karakter 2 ada 1 huruf
karakter 5 ada 1 huruf
karakter 6 ada 1 huruf
karakter 4 ada 2 huruf
---------
$input = "1112332666"
output = 
karakter 1 ada 3 huruf

Notice: Undefined offset: 1 in E:\RieqyNS13\PHP\test.php on line 17

Notice: Undefined offset: 1 in E:\RieqyNS13\PHP\test.php on line 17
karakter  ada  huruf

Notice: Undefined offset: 2 in E:\RieqyNS13\PHP\test.php on line 17

Notice: Undefined offset: 2 in E:\RieqyNS13\PHP\test.php on line 17
karakter  ada  huruf
karakter 2 ada 2 huruf