### About the Number 8400 (eight thousand four hundred)

GDT uses FreeFind.com as the search engine on his Learning About Computing website. GDT received the following email message from FreeFind.com on 4 December 2011.

```   Our search engine has finished indexing your site:
Site URL: http://shell.deru.com/gdt/
```

This was the first time that FreeFind indexed 8400 pages. In addition, rarely does FreeFind index count equal a number that is a multiple of both 10 and 100.

```   MathBabbler Number Analyst (MBNA) output:
=========================================
8400 is a natural, whole, integer
8400 is even
8400 proper divisors are: 1,2,3,4,5,6,7,8,10,12,14,15,16,20,21,24,25,
28,30,35,40,42,48,50,56,60,70,75,80,84,100,
105,112,120,140,150,168,175,200,210,240,280,
300,336,350,400,420,525,560,600,700,840,1050,
1200,1400,1680,2100,2800,4200,
8400 is refactorable (evenly divisable by # of divisors)
8400 is abundant (sum of divisors is 22352)
8400 is unhappy
8400 is not a Squarefree Number: 4,16,25,100,400,
8400 is not prime
8400 has the prime factors: 2*2*2*2*3*5*5*7 (sum=28)
8400 sum of prime factors is: 28
8400 is pentagonal
8400 in octal is 020320
8400 in binary is 10000011010000 (is evil)
8400 nearest square numbers: -119...64 (8281...8464 [92])
sqrt(8400) = 91.6515
ln(8400) = 9.03599
log(8400) = 3.92428
8400 reciprocal is .00011904761904761904761904761904
8400 is an apocalyptic power
8400! is inf
8400 is 2673.8 Pi years
8400 is 420 scoreyears
8400 = 2101^2 - 2099^2 and 2 * (2101 + 2099) = 8400
```

Note: This nBAB for the number `8400` was the 468th nBAB and it was the first nBAB created using a version of the MBNA that checked for Squarefree Numbers.

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 06 December 2011