Как не нужно удалить цифры из строки на PHP

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<?php

$words = preg_replace('/0/', '', $words ); // remove numbers
$words = preg_replace('/1/', '', $words ); // remove numbers
$words = preg_replace('/2/', '', $words ); // remove numbers
$words = preg_replace('/3/', '', $words ); // remove numbers
$words = preg_replace('/4/', '', $words ); // remove numbers
$words = preg_replace('/5/', '', $words ); // remove numbers
$words = preg_replace('/6/', '', $words ); // remove numbers
$words = preg_replace('/7/', '', $words ); // remove numbers
$words = preg_replace('/8/', '', $words ); // remove numbers
$words = preg_replace('/9/', '', $words ); // remove numbers