of a natural number (including zero) is the next natural number and is the result of adding one to that number. The predecessor of a natural number (excluding zero) is the previous natural number and is the result of subtracting one from that number. For example, the successor of zero is one, and the predecessor of eleven is ten (' and '). Every natural number has a successor, and every natural number except 0 has a predecessor.

The natural numbers have a total ordering.