7

This number is a prime.

Just showing those entries submitted by 'Gupta': (Click here to show all)

+ There are 7 letters in TUESDAY, which is the only day of the week whose name contains a prime number of letters. [Gupta]

+ The only prime whose sum of divisors (p+1) is a cube. [Gupta]

+ 1!*2!*3!*4!*5!*6!*7! ± 1 are twin primes. [Gupta]

+ All multidigit Fermat numbers end in 7. [Gupta]

+ Largest known prime which is the sum of first n Fibonacci numbers (case n=4), i.e. 7 = 1+1+2+3. [Gupta]

+ The pH value of pure water is 7. [Gupta]

+ The smallest prime such that the previous two primes AND the next two primes are twin primes. [Gupta]

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