<?php
 
function toBase($num, $b=62) {
  $base='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
  $r = $num  % $b ;
  $res = $base[$r];
  $q = floor($num/$b);
  while ($q) {
    $r = $q % $b;
    $q =floor($q/$b);
    $res = $base[$r].$res;
  }
  return $res;
}
 
function toTen( $num, $b=62) {
  $base='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
  $limit = strlen($num);
  $res=strpos($base,$num[0]);
  for($i=1;$i<$limit;$i++) {
    $res = $b * $res + strpos($base,$num[$i]);
  }
  return $res;
}
 
echo toBase('79268757439');
 
echo '<br>'.PHP_EOL;
 
echo toTen('1owzCVN');

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