Problems & Puzzles: Collection 20th

Coll.20th-011. One more as 43*47=2021

On April 6, 2018, Giovanni Resta wrote:

One may notice that the product of the two consecutive
primes 43 and 47 is equal to the concatenation of 2 consecutive integers:

43 * 47 = 2021

Q1 Find another pair of consecutive primes whose product is the
concatenation of two consecutive integers in ascending order.

Q2
Similarly, find a pair of consecutive primes whose product is a concatenation of two consecutive integers in descending order.


 


Records   |  Conjectures  |  Problems  |  Puzzles