[math-fun] Number of factors

A semiprime is the product of two primes. On my site, I wondered about the difficulty in identifying semiprimes. I picked googol+37 as an example. Don Reble sent me a note that this is *not* a semiprime.

For example, is 10^100+37 a semiprime?

10^100+37 is 87719765535727771 times a composite number; -- Don Reble Are there any good semiprimality tests? Is there any way of counting the number of factors in a big number other than factoring it? (I know that googolplex+10 has been partially factored into more than 50,000 primes, and one huge composite.) --Ed Pegg Jr