2221 and 22221 - 22212 are both prime. [Luhn]
The first four-digit prime which has only one odd digit. [Fentsor]
2221 is the largest prime that can be expressed as the sum of three different three-digit zeroless palindromic primes. I.e., 2221 = 373 + 919 + 929. [Opao]
The next prime happy-go-lucky year will be 2221. The number 2221 is simultaneously a happy number and a lucky number.
The smallest prime such that if reduced by one, has 1, 2 and 3-digit factors. [Gallardo]
2221 = 1^2 + 1^3 + 2^5 + 3^7 is the sum of the
first 4 Fibonacci numbers raised to the powers of the first
4 primes. Curiously, it is concatenated from entirely
Fibonacci number digits. Note that 2221 is prime. [Post]
The number of positive-integer Proximate-Prime
Polynomials derived from 4 successive primes under
1000000. [Capelle]
To link to this page use http://primes.utm.edu/curios/page.php?number_id=588
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