About the Number 405 (four hundred five)

405 was the smallest number that didn't have a nBAB on 19 Febuary 2017.

MathBabbler Number Analyst (MBNA) output:
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405 is natural, counting, whole, integer
405 is odd (not even)
405 is not extremely odd
405 proper divisors are: 1,3,5,9,15,27,45,81,135,
405 has 9 proper divisors
405 is deficient (sum of divisors is 321; ratio: 0.792593)
405 is unhappy
405 is not a Squarefree Number: 9,81,
405 is Harshad (Niven) number
405 is composite (not prime)
405 has the prime factors: 3*3*3*3*5 (sum=17)
405 is a 5-smooth number
405 is the sum of 3 distinct cubes (4^3 + 5^3 + 6^3)
405 is *not* arithmetic (A003601)
405 in octal is 0625
405 in hexadecimal is 0x195
405 in binary is 110010101 (is odious)
405 nearest square numbers: -5...36 (400...441 [21])
sqrt(405) = 20.1246
ln(405) = 6.00389
log(405) = 2.60746
405! is 6.80653e+881
405 is 128.916 Pi years
405 is 20 score and 5 years
405 written as a Roman numeral is CDV
405 is 203^2 - 202^2 and 203 + 202 = 405
405 is a multiple of 5 & it contains a 5 (A121025)
                     _________
405 reciprocal is 0.0024691358
remainders: 
1,10,100,190,280,370,55,145,235,325,10

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 19 February 2017

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This work is licensed under a Creative Commons Attribution 3.0 United States License.