i would say superstition. numbers can have meaning but ( i think) rarely as a blatant "sign".... example, a couple weeks ago i was sitting out back and had just finished putting up a couple bird houses at the pond. i realized i now had 9 houses, 9 feeders, 9 of something else and so on.... it was then i realized 9 is the number of completion. not as in an ending, but as a path or doorway to a new beginning. the cycle of life, blah, blah,....
numerology, prophesy, etc.. often comes with a twist in that it doesnt always play out in the ways we think it will. it is rarely a straight forward, easy to follow course to come to fruition. so in my personal opinion seeing, say three numbers like 777 or such and then playing those in the lottery is more superstition (or wishful thinking) than a sign or prophesy.... i think first you have to ask yourself "what could it mean?" "is this significant to where i am in life?" etc... and/or question what your own definition of a sign even is. and be open minded and know that a sign, prophesy or whatever isnt what YOU want IT or the outcome to be, it is ONLY what the truth, destiny, fate, whatever, WILL be