2

This number is a prime.

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

Any number with only two positive divisors is a prime number. [Gupta]

The floor function of phi^phi = 2, where phi is Golden Ratio. [Gupta]

!2 + 1 is prime. Note that !2 represents subfactorial 2. [Gupta]

The smallest number and only prime such that prime(n)=sigma(n). [Gupta]

Only prime whose sum of divisors is odd. [Gupta]

Two wrongs do not make a right. [Gupta]

The only oblong prime. [Gupta]

The smallest difference between two palindromic times (9:59:59 and 10:00:01) is 2 seconds. [Gupta]