140 (number)

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139 140 141
Cardinal one hundred forty
Ordinal 140th
(one hundred fortieth)
Factorization 22 × 5 × 7
Divisors 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140
Greek numeral ΡΜ´
Roman numeral CXL, cxl
Binary 100011002
Ternary 120123
Senary 3526
Octal 2148
Duodecimal B812
Hexadecimal 8C16

140 (one hundred [and] forty) is the natural number following 139 and preceding 141.

Contents

In mathematics

140 is a square pyramidal number. Square-pyramidal-140.png
140 is a square pyramidal number.

140 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.

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 fields

140 is also:

References

  1. "Sloane's A001599 : Harmonic or Ore numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
  2. Wired.com - June 23, 2009