About the Number 280 (two hundred eighty)

280 was the smallest number that didn't have a nBAB on 14 April 2016. MathBabbler is trying to ensure that the numbers 0-300 have nBABs by the end of the Spring 2016 Semester. With the posting of this nBAB for 280, 282 became the smallest number without a nBAB on 14 April 2016.

MathBabbler Number Analyst (MBNA) output:
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280 is a natural, whole, integer
280 is even
280 proper divisors are: 1,2,4,5,7,8,10,14,20,28,35,40,56,70,140,
280 has 15 proper divisors
280 is abundant (sum of divisors is 440; ratio: 1.57143)
280 is happy
280 is not a Squarefree Number: 4,
280 is Harshad (Niven) number
280 is composite (not prime)
280 has the prime factors: 2*2*2*5*7 (sum=18)
280 is a 7-smooth number
280 is Arithmetic (A003601)
280 is the sum of 6 consecutive primes
280 = 37 + 41 + 43 + 47 + 53 + 59
280 in octal is 0430
280 in hexadecimal is 0x118
280 in binary is 100011000 (is odious)
280 nearest square numbers: -24...9 (256...289 [17])
sqrt(280) = 16.7332
ln(280) = 5.63479
log(280) = 2.44716
280 reciprocal is .00357142857142857142857142857142
280! is 1.67723e+565
280 is 89.1268 Pi years
280 is 14 scoreyears
280 written as a Roman numeral is CCLXXX
280 is 71^2 - 69^2 and 2 * (71 + 69)
280 is a multiple of 2 & it contains a 2 (A121022)
280 is a multiple of 8 & it contains a 8 (A121028)
280 is a multiple of 28 & it contains a 28

log6(280) = 3.14484, which when rounded to the nearest hundredth (3.14) equals Pi (3.14159265...) rounded to the nearest hundredth.

Update::2017.11.08

Twitter Inc. announced had increased the maximum tweet length from 140 characters to 280 characters.

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 14 April 2016