5

This number is a prime.

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

Euclid gave 5 postulates of plane geometry. [McCranie]

A polynomial equation of degree 5 and higher cannot be solved algebraically using radicals. [Nie]

There are 5 months of the year with a prime number of letters. [Nie]

The only prime number that is one less than a perfect number. [Nie]

Are there any integers n for which σ(σ(n)) = 5n, where σ(n) denotes the sum of all positive divisors of n? [Nie]

The only prime number that is both a sum and difference of two primes. [Nie]