12920
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 32400
- Proper Divisor Sum (Aliquot Sum)
- 19480
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4608
- Möbius Function
- 0
- Radical
- 3230
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 4
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
- 76
- 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
- Expansion of (1-4*x)^(7/2).at n=14A002423
- a(n) = floor(n*(n-1)*(n-2)*(n-3)/9).at n=20A011919
- Expansion of e.g.f. sinh(sin(x)*log(x+1)).at n=8A012284
- a(n) = n*(9*n-2).at n=38A013656
- Expansion of (1-4*x)^(19/2).at n=13A020931
- Expansion of (1-4*x)^(19/2).at n=14A020931
- Fibonacci sequence beginning 0, 5.at n=18A022088
- Perimeters of more than one primitive Pythagorean triangle.at n=19A024408
- Expansion of 1/((1-5x)(1-8x)(1-9x)(1-12x)).at n=3A028192
- Numbers k such that 183*2^k+1 is prime.at n=29A032468
- Layer counting sequence for hyperbolic tessellation by regular pentagons of angle Pi/2.at n=9A054888
- a(n) = (n/2)*(n + 1)*(3*n + 11).at n=18A059997
- Numbers of the form (2i)! (2j)! / i! j! (i + j)!.at n=41A068514
- Numbers k such that binomial(prime(k), k) is divisible by k^2.at n=35A081384
- Recamán's Fibonacci variation : a(1)=a(2)=1 then a(n) = a(n-1)+a(n-2)-F(n) if that number is >0 and not already in the sequence; a(n) = a(n-1)+a(n-2)+F(n) otherwise where F(n) denotes the n-th Fibonacci number.at n=21A091484
- Series reversion of y + y^2 + y^3.at n=14A103779
- a(n) = 4 + floor((3 + Sum_{j=1..n-1} a(j))/4).at n=36A120163
- Numbers k such that the central binomial coefficient C(2k,k) is divisible by k^2.at n=25A121943
- Numbers n such that sigma(n) and sigma(sigma(n)) are both perfect squares.at n=6A134263
- a(n) = n*(8*n+3).at n=40A139276