Prime Curios!: 72

72
(another Prime Pages' Curiosity)

Curios:

Index
Keywords
Home
Glossary
The book!
Previous
Next
Random

Curios Search: Participate:

Mail Editor
Submit Curio
Prime Puzzio
Test Number

If we use 3 instead of 2 in the formula for perfect numbers we get 3²(3² - 1) = 72, which lies between a twin prime pair. [Gundrum]

72 is the only number of the form p^q * q^p that lies between a twin prime pair, where p and q are distinct primes. [Kulsha]

The maximum difference between two consecutive five-digit primes (31397 and 31469). [Gallardo]

The smallest number that can be expressed as a sum of two primes, each ending with the digit 1, in two different ways (72 = 11 + 61 = 31 + 41). [Schlesinger]

72 is the smallest number that can be expressed as the difference of the squares of consecutive primes in two distinct ways, i.e., 72 = 19^2 - 17^2 = 11^2 - 7^2. [King]

To link to this page use http://primes.utm.edu/curios/page.php?number_id=575