If my calculations are right the best way to find a BIG prime number is to iterate through all the prime numbers before it, why? Because the quickest way to check a prime is to see if it is divisible by all the previous primes, I am not going to waste any processing power on non prime can be defined with prime numbers like 63 = 7*3^2.

So here is my first attempt to find that BIG prime. (With BIG prime a mean a 100 digit number)

The code below is my first prototype, I still need to save the prime that I found on a DB so that I don’t need to start from 1 all the time I start the code:

# Python program to calculate prime numbers
import math
import numpy
import sqlite3

primeList = [2,3, 5, 7, 11, 13, 17, 19, 23, 29 ]

def isPrime(num):
  # prime numbers are greater than 1
  if num > 1:
  # check for factors
  for i in range(len(primeList)):
    if (num % primeList[i]) == 0:
      #print(num,"is not a prime number")
      #print(i,"times",num//i,"is",num)
      break
  else:
    print(num,"is a prime number")
    primeList.append(num)
    #add_prime(num)

  # if input number is less than
  # or equal to 1, it is not prime
  else:
    print(num,"is not a prime number")

num = 30
while True:
  isPrime(num)
  num = num +1
  if num == math.pow(10, 101):
    break

Below are more posts about Prime numbers.

• Prime number 2. The sqlite strikes back! In this post I add sql so that I can stop and and restart where I left.
• Multi Threading and still looking for Primes. In this post I make the most of my laptop processing power.
•  Sieve Of Eratosthenes (Still on Prime). The quickest way to find a 8 digit prime number.