1676
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 2940
- Proper Divisor Sum (Aliquot Sum)
- 1264
- 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
- 836
- Möbius Function
- 0
- Radical
- 838
- Omega Function (Ω)
- 3
- 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
- 42
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Number of permutations of an n-sequence discordant with three given permutations (see reference) in n-6 places.at n=2A000492
- Number of n-input 2-output switching networks under the action of S(n) on the inputs and S(2) and complementing group C(2,2) on the outputs.at n=2A000856
- a(n) = a(n-1) + a(n-2) + F(n) - 1, a(0) = a(1) = 0, where F() = Fibonacci numbers A000045.at n=13A006478
- Coordination sequence T4 for Zeolite Code AFR.at n=31A008022
- Coordination sequence T2 for Zeolite Code CAS.at n=25A008064
- Coordination sequence T1 for Zeolite Code DAC.at n=26A008067
- Coordination sequence T4 for Zeolite Code FER.at n=25A008109
- Coordination sequence T5 for Zeolite Code GOO.at n=28A008115
- Coordination sequence T7 for Zeolite Code MTW.at n=27A008202
- Coordination sequence for quartz.at n=23A008261
- Numbers k such that phi(k) + 10 | sigma(k + 10).at n=40A015789
- Number of lines through exactly 9 points of an n X n grid of points.at n=47A018816
- Numbers k such that the continued fraction for sqrt(k) has period 36.at n=13A020375
- Index of 5^n within sequence of numbers of form 3^i*5^j.at n=47A022338
- Expansion of sin(sin(x)*x)/2.at n=4A024237
- Index of 7^n within the sequence of the numbers of the form 4^i*7^j.at n=48A025722
- T(n, 2*n-4), T given by A027960.at n=12A027966
- a(n) = n^2 - 5.at n=41A028875
- Positions of record values in A030787.at n=39A030792
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 20.at n=26A031518