Mercury is a smallest and neutral planet that changes according to its placement in signs and houses. It is the nearest planet to Sun and thus is restless, Mercury is around 37000000 miles away from earth, whose temperature is around 350 degree cc and makes a complete revolution of Sun in only 88 days. Fast changing and fickle in nature.
It rules education, writers, businessman, intestines, lungs and nervous system. Both Jupiter and Mercury represent human intelligence, Mercury indicates an immature side of intelligence as compared to the more mature one of Jupiter. It rules all means of communication and intermediation. Body parts indicated by Mercury: Mercury rules over the arms, ear hearing system, and the nervous system. Inauspicious Mercury can make person unstable mind, does not trust easily, selfish, clever, doubtful. It is a dual natured planet and owns the dual natured signs, Virgo and Gemini .
5 no. represents Mercury in numerology.
Virgo and 
Gemini .
