2071
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2200
- Proper Divisor Sum (Aliquot Sum)
- 129
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1944
- Möbius Function
- 1
- Radical
- 2071
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 125
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that (1,k) is "good".at n=27A000696
- a(n+6) = -a(n+5) + a(n+4) + 3a(n+3) + a(n+2) - a(n+1) - a(n). a(n) = sign(n) if abs(n)<=3.at n=27A001945
- Central polygonal numbers: a(n) = n^2 - n + 1.at n=46A002061
- G.f.: -1 + Product_{k>=1} (1 + prime(k)*x^prime(k)).at n=26A002099
- Number of sensed planar maps with n edges.at n=6A006384
- Crystal ball sequence for diamond.at n=13A007904
- Coordination sequence T1 for Zeolite Code MEI.at n=33A008146
- Coordination sequence T1 for Zeolite Code MEP.at n=27A008157
- Coordination sequence T5 for Zeolite Code CON.at n=32A009872
- Coordination sequence T1 for Zeolite Code VET.at n=28A009902
- Expansion of (2-2*x-x^2)/((1-2*x^2)*(1-x)^2).at n=22A016724
- Fermat pseudoprimes to base 4.at n=19A020136
- Pseudoprimes to base 16.at n=25A020144
- Pseudoprimes to base 27.at n=20A020155
- Pseudoprimes to base 34.at n=29A020162
- Pseudoprimes to base 43.at n=32A020171
- Pseudoprimes to base 45.at n=22A020173
- Pseudoprimes to base 46.at n=29A020174
- Pseudoprimes to base 63.at n=10A020191
- Pseudoprimes to base 66.at n=11A020194