Answer: No

Answer: A perfect number.
You might also think of a perfect number as a number that is half the sum of all of its positive divisors, including itself! This definition is at least 2300 years old as it appears in Euclid's "Elements".

Answer: 3
Russell collaborated very little and no Erdös number can be found using research articles. But, as pointed out by Sachi Sri Kantha at "the Erdös number project" Russell and Albert Einstein did coauthor the Russell-Einstein "Peace" Manifesto of 1955.

Answer: Infinite

Answer: 180 degrees
The angles of a triangle always sum to 180 degrees.

Answer: 73

Answer: 91

Answer: 49

Answer: Pierre-Simon Laplace has an Erdős number of at most 14!
According to "The Erdös number project" a path to Laplace was found by Leonid Yanushevich giving the famous mathematician an Erdös number of at most 14.

Answer: 160