Question 143
a) Prove that the numbers of the positive divisors of $137$, $138$ and $139$ are integer powers of $2$.
b) What is the largest number of consecutive positive integers such that each of them has the number of its positive divisors a power of $2$?
b) What is the largest number of consecutive positive integers such that each of them has the number of its positive divisors a power of $2$?