How to find BIG prime numbers

Python

PrimeNumbersHundredsChart 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

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