Who can find the largest prime number with the own programmed code?

import math

maxind = 1500000000  # let's calculate prime numbers smaller than 1.5 billion
primesarray = [True] * (maxind + 1)
amount = maxind
number = 0
ind = 0
squareroot = 0.0
candinate = 0
helper = 0def is_prime_number(num):
    if num % 2 == 0:
        return False
    else:
        index = 3
        itis = True
        while index <= math.isqrt(num) and itis:
            if primesarray[index]:
                if num % index == 0:
                    itis = False
                    print(index)
            index += 2
        return itisamount = maxind
squareroot = math.isqrt(amount)
for ind in range(2, maxind + 1):
    primesarray[ind] = True  # let's suppose all are primes
primesarray[1] = False
number = 2
ind = number

while ind <= amount:
    primesarray[ind] = False  # remove 2's multiplies
    ind += 2

while number < squareroot:
    while primesarray[number] is False and number < squareroot:
        number += 1  # let's find next prime number
    ind = number + number
    while ind < amount:  # remove its multiplies
        primesarray[ind] = False
        ind += number
    number += 1

primesarray[2] = True
# Prime numbers smaller than a billion have now been tabulated.
# Let's print a hundred smaller ones as a test.
for ind in range(1, 101):
    if primesarray[ind]:
        print(ind)

# let's examine candidate number
helper = 1
while helper < 20:
    candinate = maxind * maxind - helper
    if is_prime_number(candinate):
        print(candinate, ' is a prime number.')
    else:
        print(candinate, ' is not a prime number.')
    helper += 2

# returns True if  2**p -1 is a mersenne prime, false otherwise
# assumes p is prime

def is_mersenneprime(p): 
    if p==2:
        return True
    mp = 2**p -1
    m = 4
    for _ in range(p-2):
        m = (m*m-2) % mp

    return (m==0)