Equations involving Euler Totient function

There are two little equations involving Euler's totient function which I'm not sure how to solve:

**(a)** Solve the equation .

**(b)** Given that is a product of two primes and that , find the Prime factorisation of __without using a factorisation algorithm__.

Attempt:

For **(a)** I know that if then the totient function is given by . And if n has prime factorization , then it is given by:

So in this case we have

So, how should I work backward to find n?

For **(b)**, since where p & q (the question doesn't say if they are distinct) are primes we'll have:

Now, how can I tell what p and q are without factorizing n?

Any guidance is greatly appreciated.