There are at least two theorems known as Chebyshev's theorem.
The first is Bertrand's postulate, proposed by Bertrand in 1845 and proved by Chebyshev using elementary methods in 1850 (Derbyshire
2004, p. 124).
The second is a weak form of the prime number theorem stating that the order of magnitude
of the prime counting function 
is
where 
denotes "is asymptotic to" (Hardy and Wright
1979, p. 9). More precisely, Chebyshev showed in 1849 that if
for some constant 
,
then 
(Derbyshire 2004, p. 123).
See also
Bertrand's Postulate,
Prime Counting Function,
Prime
Number Theorem
Explore with Wolfram|Alpha
References
Derbyshire, J. Prime Obsession: Bernhard Riemann and the Greatest Unsolved Problem in Mathematics.
New York: Penguin, 2004.Hardy, G. H. and Wright, E. M. An
Introduction to the Theory of Numbers, 5th ed. Oxford, England: Clarendon
Press, 1979.Referenced on Wolfram|Alpha
Chebyshev's Theorem
Cite this as:
Weisstein, Eric W. "Chebyshev's Theorem."
From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ChebyshevsTheorem.html
Subject classifications
