There are 5,761,455 primes less than 100,000,000. The largest of which is 99,999,989.
Infinate
10
Ten of them.
The only consecutive primes between 1 and 100 are 2 and 3.
One pair of twin primes between 135 and 145
There are 57 such numbers.
One of them.
25 of them.
There are five of them, including the number 1.
There are four pairs of twin primes between 2 and 35: (5,7) (11,13) (17,19) (29,31).
All pairs of two primes are coprime. There are fifteen primes under 50. So that means there are 105 unique pairs of "coprime primes", or more generally, pairs of primes, under 50.