How to get category name by product id in magento?

You can get category name by product id by following code. Where You want display category name, put the code.

<?php $product = Mage::getModel('catalog/product')->load($_product->getId());
$cats = $product->getCategoryIds();
foreach($cats as $categoryId) {
    $category = Mage::getModel('catalog/category')->load($categoryId);
    echo $category->getName();
}
?>