# Number Recreations

Shyam Sunder Gupta
IRSE, FIE, FIPWE,
Former Principal Chief Engineer,
North Western Railway, Jaipur, India-302017
email: guptass@rediffmail.com
http://www.shyamsundergupta.com/
 What is New? (Update 28 April, 2024) A new 32114-digit, easy-to-remember prime reported by me on the Number Theory Mailing List on March 7, 2024 was featured in the Dutch national daily newspaper NRC on Saturday, April 13, 2024, by Alex van den Brandhof (a science journalist). The page on Happy Numbers added. CYF NO. 59 Contribution by Al Zimmermann, Giorgos Kalogeropoulos and Alessandro Casini given. Prime curios 7, 97, 131, 270, 491, 631, 882, 1621, 2477, 62745, 546289, 245044800, 47167...14213 (28-digits), 23456...89123 (32114-digits). added. My Book Creative Puzzles to Ignite Your Mind published by SPRINGER was featured in "The Guardian" (UK). Mr. Alex Bellos, in his biweekly puzzle column in the Guardian covered some simple puzzles from my book. Can you solve it? The man who made India's trains run on time Did you solve it? The man who made India's trains run on time My Paper Amazing Shapes Using Factorial Digits is published in the November 2023 issue of "At Right Angles". The page on Fascinating Triangular Numbers updated.

### Do You Know?

A prime factorization in which each of the ten digits from 0 to 9 appear just once:
28651 = 7 * 4093

### Can You Find?

CYF NO. 60
A multidigit palindromic number which can be represented as the product of three consecutive numbers except the following: 474474 = 77 * 78 * 79

email your answer

### Contents

Note: The above topics including many more will be added in due course.

### My Contributions in Prime Curios

Prime Curios! - site maintained by G. L. Honaker Jr. and Chris Caldwell

I ranked second among the prime curios submitters in the world, with more than 1300 prime curios that list interesting things about prime numbers.

### My Favorite Links

• Magic Squares,Magic Stars and Other Interesting number patterns by Harvey Heinz
• Mudd Math Fun Facts pages
• On-Line Encyclopedia of Integer Sequences OEIS
• Math Puzzles
An interesting site with lot of math recreations by Ed Pegg Jr.

### My Favorite Books

Recommended list of books for those interested in Recreational and Computational Number theory

 (January, 2003) (March, 2003) (October, 2003)

Send me e-mail at guptass@rediffmail.com

This page was last updated on 28th April, 2024.

Copyright © 2024-2025 Shyam Sunder Gupta. All rights reserved.