2281

This number is a prime.

The smallest prime number which is a sum of distinct multidigit primes beginning and ending with the digit seven: 2281 = 727 + 757 + 797. [Capelle]

Index p of the largest known perfect number 2^{p - 1}(2^p - 1) having both a prime subscript (17) and a prime number of digits (1373). [Beedassy]

The only known Mersenne prime exponent whose product of digits is a power of two (2*2*8*1 = 2^5). [Arf]