# Gigantic Palindromic Prime

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## Theorem

The integer defined as:

- $10^{11 \, 810} + 1 \, 465 \, 641 \times 10^{5902} + 1$

is a gigantic prime which is also palindromic.

That is:

- $1(0)_{5901}1465641(0)_{5901}1$

where $\left({a}\right)_b$ means $b$ instances of $a$ in a string.

## Proof

It is clear that this number is palindromic.

It is also noted that it has $1 + 5901 + 7 + 5901 + 1 = 11 \, 811$ digits, making it gigantic.

It was checked that it is a prime number using the "Alpertron" Integer factorisation calculator on $6$th March $2022$.

This took approximately $4$ minutes.

## Sources

- 1994:
*Palindromic Primes with a Palindromic Prime Number of Digits*(*J. Recr. Math.***Vol. 26**,*no. 4*: p. 256)

- 1997: David Wells:
*Curious and Interesting Numbers*(2nd ed.) ... (previous) ... (next): $10_{5901}14656410_{5901}1$