#10: Summation of primes | Ben Cunningham

# #10: Summation of primes

Problem by Project Euler · on February 8, 2002

The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.

Find the sum of all the primes below two million.

# Python

def is_prime(x):

if x < 4:
return True

if x % 2 == 0:
return False

for fac in range(3, int(x ** (1/2.0)) + 1, 2):
if x % fac == 0:
return False

return True

ans = 2
for n in range(3, 2000000, 2):
if is_prime(n):
ans += n

print(ans)

## 142913828922