| 词条 | 140 (number) |
| 释义 |
| number = 140 | divisor = 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140 }} 140 (one hundred [and] forty) is the natural number following 139 and preceding 141. In mathematics140 is an abundant number and a harmonic divisor number.[1] It is the sum of the squares of the first seven integers, which makes it a square pyramidal number, and in base 10 it is divisible by the sum of its digits, which makes it a Harshad number. 140 is an odious number because it has an odd number of ones in its binary representation. The sum of Euler's totient function φ(x) over the first twenty-one integers is 140. 140 is a repdigit in bases 13, 19, 27, 34, 69, and 139. In other fields140 is also:
See also
References1. ^{{Cite web|url=https://oeis.org/A001599|title=Sloane's A001599 : Harmonic or Ore numbers|last=|first=|date=|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-27}} 2. ^[https://www.wired.com/geekdad/2009/06/the-140-project-filmmakers-capture-140-seconds-of-home/ Wired.com - June 23, 2009] External links{{Commons cat|140 (number)}}
1 : Integers |
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