## Friday, January 13, 2012

### 438

438 = 2 x 3 x 73.

438 is a Smith number because the sum of its digits is equal to the sum of the digits of its prime factors: 4 + 3 + 8 = 2 + 3 + 7 + 3 = 15.

438 is 110110110 in base 2 (binary) and 666 in base 8. It is 3223 in base 5 and 141 in base 19.

438 divides 656 - 1.

438 is the sum of 10 positive 5th powers: 438 = 35 + 25 + 25 + 25 + 25 + 25 + 25 + 15 + 15 + 15.

The term "438 match" or "438 game" has been used by cricket news media to describe the famous 2006 One Day International in which Australia scored a world record 434 in their innings, only to see South Africa respond in their innings with 438.

#### 1 comment:

rafparmat@gmail.com said...

Orden multiplicativo:
Como 21^2>438>20^2, y los primos equidistantes son 23 y 19
23^36(mód.438) = 1 y 19^36(mód.438) =1 son ordenes multiplicativos.
Ecuación Pell
293^2-438*14^2 = 1 es la Ecuación Pell.
http://math.fau.edu/richman/pell-m.htm
http://en.wikipedia.org/wiki/Gaussian_integer
http://hojamat.es/parra/gaussiana.pdf
438=x^2+Dy^2 = 17^2+149*1^2
438=(17+(-149)^(1/2)) (17-(-149)^(1/2)=17+-(149)^(1/2))i.
438=x^2+Dy^2 = 31^2-523*1^2
438=(31+(523)^(1/2)) (31-(523)^(1/2))=31+-(523)^(1/2))