Looking at the code of [node_save()][1], which the function used to save a node, the hooks that are invoked after drupal_write_record(), which is the function used to set the node ID, are the following ones (when the node is created):

- [hook_node_insert()][2]
- [hook_entity_insert()][3]

<!-- break -->

    // Call the node specific callback (if any). This can be
    // node_invoke($node, 'insert') or
    // node_invoke($node, 'update').
    node_invoke($node, $op);

    // Save fields.
    $function = "field_attach_$op";
    $function('node', $node);

    module_invoke_all('node_' . $op, $node);
    module_invoke_all('entity_' . $op, $node, 'node');


  [1]: http://api.drupal.org/api/drupal/modules--node--node.module/function/node_save/7
  [2]: http://api.drupal.org/api/drupal/modules--node--node.api.php/function/hook_node_insert/7
  [3]: http://api.drupal.org/api/drupal/modules--system--system.api.php/function/hook_entity_insert/7