def _get_latest_checkpoint_number(latest_checkpoint):
    """Get latest checkpoint number from latest_checkpoint.
    Return None if latest_checkpoint is None or failed to get number
    """
    checkpoint_number = None
    if latest_checkpoint and isinstance(latest_checkpoint, str):
        if '-' in latest_checkpoint:
            number_str = latest_checkpoint.rsplit('-', 1)[1]
            if number_str.isdigit():
                checkpoint_number = int(number_str)
    return checkpoint_number