12912
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 33480
- Proper Divisor Sum (Aliquot Sum)
- 20568
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4288
- Möbius Function
- 0
- Radical
- 1614
- Omega Function (Ω)
- 6
- 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
- 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
- a(1) = 5; a(n+1) = a(n)-th nonprime, where nonprimes begin at 0.at n=36A025001
- a(n) = a(n-1) + 2*a(n-2) - 2*a(n-3) + a(n-5).at n=20A116157
- Number of closed knight's tour diagrams of a 3 X n chessboard that have "Bergholtian symmetry".at n=22A169766
- Triangle read by rows: T(n,k) is the number of 2-compositions of n having k columns in which the top entry is equal to the bottom entry (0<=k<=floor(n/2)).at n=26A181299
- Total sum of parts <= n of multiplicity 0 in all partitions of n.at n=14A213679
- G.f.: x^4*(2 - x^2 + x^3 + x^4)/(1-x-x^2)^3.at n=15A229732
- Least number k such that (n!+k)/n and (n!-k)/n are both prime.at n=45A245697
- G.f. A(x) satisfies: A(x) = 1 + x*A(x)^2 - x^2/A(x)^3.at n=10A295498
- a(0)=1; a(1)=1; for n >= 2, a(n) = a(n-A000120(n)) + a(n-1-A023416(n)).at n=35A297216
- Dirichlet convolution of the integer partition numbers A000041 with the number of divisors function A000005.at n=34A323766
- Expansion of e.g.f. 1/(1 - log(1 + x))^3.at n=7A354120
- a(n) is the smallest number k such that A358351(k) = n.at n=6A358352
- Concatenate the terms of A027750 (omitting spaces and commas), chop into blocks of length 5, then omit any leading zeros.at n=25A362446