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This number is a composite.
There are 80 four-digit primes which are concatenations of two-digit primes. [De Geest]
(1080 - 80)/80 is prime. [Luhn]
80^(80+1) + (80+1)^80 is prime.
The largest natural number n such that all prime factors of n and n+1 are smaller or equal to the prime digit 5. [Capelle]
The only two-digit integer n that yields a prime in the form n^(n+1)+(n+1)^n. [Silva]
The smallest integer n such that both n and n+1 are products of at least 4 primes. [Post]
Theoretically, the fewest prime factors in the numbers spanning a non-trivial 8-tuple. [Merickel]
(There is one curio for this number that has not yet been approved by an editor.)
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