2158
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3528
- Proper Divisor Sum (Aliquot Sum)
- 1370
- 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
- 984
- Möbius Function
- -1
- Radical
- 2158
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 50
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Worst cases for Pierce expansions (numerators).at n=20A006537
- 7th-order maximal independent sets in path graph.at n=50A007381
- a(n) = n OR n^2 (applied to binary expansions).at n=45A007745
- Coordination sequence T5 for Zeolite Code AET.at n=32A008011
- Coordination sequence T1 for Zeolite Code AFT.at n=35A008026
- Coordination sequence T8 for Zeolite Code EUO.at n=29A008103
- Coordination sequence T2 for Zeolite Code YUG.at n=30A008248
- 3x+1 sequence starting at 63.at n=57A008874
- 3x+1 sequence starting at 95.at n=55A008875
- 3x+1 sequence starting at 27.at n=61A008884
- Coordination sequence T2 for Zeolite Code AFX.at n=35A009865
- Coordination sequence T3 for Zeolite Code RSN.at n=30A009887
- a(0) = 1, a(n) = 11*n^2 + 2 for n>0.at n=14A010003
- Coordination sequence T6 for Zeolite Code TER.at n=31A016438
- Numbers k such that the continued fraction for sqrt(k) has period 30.at n=24A020369
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Lucas numbers), t = (F(2), F(3), ...).at n=11A024472
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Lucas numbers), t = (F(2), F(3), F(4), ...).at n=10A025092
- T(n,0) + T(n,1) + ... + T(n,n), T given by A026692.at n=10A026699
- Coordination sequence T1 for Zeolite Code CFI.at n=31A033599
- Coordination sequence T3 for Zeolite Code STF.at n=31A038442