In maths an inverse is often written in text books as the number (in this case 14) with an integer of -1.
I thought you might find this bit of information useful even though the answer above is quite correct.
Supplement from 01/04/2009 11:55am:
Should have said to the power of -1 rather than use the term integer.
Better to say 1/14 is the reciprocal of 14. The multiplicative inverse is 1/14, the additive inverse is -14. Informally plenty of people say inverse when they mean multiplicative inverse (=reciprocal).
There are of course other types of arithmetic. Here we are using rational numbers. One could answer the question in modulo arithmetic too.