## 4659775785220018543264560743076778192897

p_{40} = 4659775785220018543264560743076778192897
is a prime number.
This can be verified from the factorization

p_{40} - 1 = 2^{12} . 3 . 5639 . 8231 . 433639 . 18840862799165386003967

The fact that p_{40} - 1 is divisible by 2^{12}
is not surprising,
since p_{40} is a factor of the Fermat number
F10.

Richard Brent

26 October 1995