Here we need Newton's law of universal gravitation:
where F is the gravitational force, G is the universal constant, `m_1` and `m_2` are masses of two objects and R is the distance between them.
So we have to know the value of G and the distance between the Sun and Venus. The Internet says that
`R=108*10^6 km=1.08*10^11 m.`
So the force exerted is
`(6.674*1.99*4.87/1.08^2)*10^(-11)*10^30*10^24*10^(-22)=55.45*10^21` = 5.545*10^22 (N).
This is the answer to the force exerted by the Sun on Venus.