﻿ Python: Print the number of prime numbers which are less than or equal to a given integer - w3resource

# Python: Print the number of prime numbers which are less than or equal to a given integer

## Python Basic - 1: Exercise-38 with Solution

Write a Python program to print the number of prime numbers that are less than or equal to a given number.

Input:
n (1 ≤ n ≤ 999,999)
Input the number(n): 35
Number of prime numbers which are less than or equal to n.: 11

Sample Solution:

Python Code:

``````primes =  * 500000
primes = 0

for i in range(3, 1000, 2):
if primes[i // 2]:
primes[(i * i) // 2::i] =  * len(primes[(i * i) // 2::i])

print("Input the number(n):")
n=int(input())
if n < 4:
print("Number of prime numbers which are less than or equal to n.:",n - 1)
else:
print("Number of prime numbers which are less than or equal to n.:",sum(primes[:(n + 1) // 2]) + 1)
``````

Sample Output:

```Input the number(n):
35
Number of prime numbers which are less than or equal to n.: 11
```

Pictorial Presentation: Flowchart: Python Code Editor:

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