0. Yes, 7 is a prime number.
All prime numbers are odd, except for one (2 is the only even prime number).
1 is not a prime number (and neither is zero) because it can't be divided by 1 or itself, because 1 is itself xD So it's not USUALLY counted as a prime (neither is zero)
Interestingly, the Fundamental Theorem of Arithmetic states that any whole number can be written as a multiplication of primes.
Like 9 = 3*3
11 is a prime so it equals 11*1
15 is 5*3
Etc, any number can be written in this way.