# §27.1 Special Notation

(For other notation see Notation for the Special Functions.)

 positive integers (unless otherwise indicated). divides . greatest common divisor of . If , and are called relatively prime, or coprime. greatest common divisor of . sum, product taken over divisors of . sum taken over , and relatively prime to . prime numbers (or primes): integers () with only two positive integer divisors, 1 and the number itself. sum, product extended over all primes. real numbers. . natural logarithm of , written as in other chapters. Riemann zeta function; see §25.2(i). Jacobi symbol; see §27.9. Legendre symbol; see §27.9.