| − | The probability that a random integer N is prime is roughly 1/ln(N), where ln(N) is the natural logarithm (base ''e'') of N.<ref>http://home.att.net/~numericana/answer/primes.htm</ref> This is a formulation of a more general statement known as the [[prime number theorem]]. | + | The number of primes smaller than a given number <math>N</math> is roughly <math>\frac{N}{\ln(N)}</math>, where <math>\ln(N)</math> is the natural logarithm (base ''e'') of <math>N</math>.<ref>http://home.att.net/~numericana/answer/primes.htm</ref> This is a formulation of a more general statement known as the [[prime number theorem]]. |