180 x (2^127 - 1) + 1/Mistake

Source Work

 * The Dictionary
 * $180 \times \paren {2^{127} - 1} + 1$
 * $180 \times \paren {2^{127} - 1} + 1$

Mistake

 * The largest known prime in July $1951$, discovered by and  of Cambridge University on the EDSAC.

Correction
That number is not a prime.

We have:

The same section then goes on to state how in the same month determined the fact that $\paren {2^{143} + 1} / 17$ is prime, using only a desk calculator.

Interestingly:

and so is not actually a multiple of $17$.

But:
 * $\paren {2^{143} + 1} / 17 = 655\,904\,270\,545\,018\,327\,692\,227\,008\,019\,069\,456\,058\,247$ remainder $10$

and $655\,904\,270\,545\,018\,327\,692\,227\,008\,019\,069\,456\,058\,247$ is indeed prime.

At $42$ digits it exceeds $30\,625\,413\,022\,884\,461\,711\,703\,714\,668\,859\,139\,030\,861$ by an order of magnitude.

This paragraph has been removed from of $1997$.