Prime number 131

 

131   is a prime number.
 

130 \; = \; 2 \; \times \; 5 \; \times \; 13
132 \; = \; 2^2 \; \times \; 3 \; \times \; 11

131   is the smallest prime for which each of the numbers   p - 1   and   p + 1
has at least three different prime divisors.

 
 
Find the next one

 
 

139   is a prime number.

138 \; = \; 2 \; \times \; 3 \; \times \; 23
140 \; = \; 2^2 \; \times \; 5 \; \times \; 7

curiously, each of the concatenations has at least three different prime divisors:

(p-1) \; || \; (q-1)
(p+1) \; || \; (q+1)

130 || 138 \; = \; 130138 \; = \; 2 \; \times \; 31 \; \times \; 2099
132 || 140 \; = \; 132140 \; = \; 2^2 \; \times \; 5 \; \times \; 6607

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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About benvitalis

math grad - Interest: Number theory
This entry was posted in Prime Numbers and tagged . Bookmark the permalink.

2 Responses to Prime number 131

  1. paul says:

    This is it

    {139,{{2,1},{3,1},{23,1}},{{2,2},{5,1},{7,1}},140,138}

    Paul.

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