HomeLanguagesPython | sympy.prevprime() method

Python | sympy.prevprime() method

19 June 2025

In sympy module, we can get the previous prime number for a given number n using sympy.prevprime() function. For n < 2^64 the answer is definitive; larger n values have a small probability of actually being pseudoprimes.

Syntax:  sympy.prevprime()
Parameter:  n; number to be tested
Return:  previous prime value

Code #1:

Python3

# Python program to get previous prime number 
# using sympy.prevprime() method 
  
# importing sympy module 
from sympy import *
  
# calling prevprime function on different numbers 
geek1 = prevprime(7) 
geek2 = prevprime(13) 
  
print(geek1) 
print(geek2)

Output:

5
11

Code #2:

Python3

# Python program to check prime number 
# using sympy.prevprime() method 
  
# importing sympy module 
import sympy.ntheory as nt 
  
# calling prevprime function on different numbers 
nt.prevprime(2)