12688
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 26908
- Proper Divisor Sum (Aliquot Sum)
- 14220
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5760
- Möbius Function
- 0
- Radical
- 1586
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 81
- 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 5-tuples of different integers from [ 2,n ] with no common factors among quadruples.at n=19A015645
- Expansion of 1/(1-x^5-x^6-x^7-x^8-x^9-x^10-x^11-x^12).at n=43A017843
- Greater of a,b where n^2 = a^3 + b^3; a,b>0 and gcd(a,b)=1. The lesser of a,b is the corresponding term in A099532 and n, which is used to order this sequence, is the corresponding term in A099426.at n=29A099533
- a(n) is the smallest positive d such that the n-th prime is the smallest prime p for which p+d is also prime.at n=26A101042
- A101042 sorted. There exists a prime p for which a(n) is the smallest positive d such that p is the smallest prime where p+d is also prime.at n=32A101043
- Terms in A112039 that are divisible by 3, divided by 3.at n=20A112040
- Number of n-digit numbers m such that m and m^10 are zeroless.at n=7A124650
- Even numbers k such that if a person is born in year k and lives not more than 100 years, then he never celebrates his prime birthday on a prime year.at n=10A124658
- A triangular sequence of six back recursive polynomial that are Hermite H(x,n) like and alternating orthogonal on domain {-Infinity,Infinity} and weight function Exp[ -x^2/2]:k=6 P(x, n) = Sum[If[Mod[m, 2] == 1, (m + 1)*x^m*P(x, n - m), n^(m/2)*P(x, n - m)], {m, 1, k}].at n=40A138093
- A triangular sequence of eight back recursive polynomials that are Hermite H(x,n) like and alternating orthogonal on domain {-Infinity,Infinity} and weight function Exp[ -x^2/2]:k=8 P(x, n) = Sum[If[Mod[m, 2] == 1, (m + 1)*x^m*P(x, n - m), n^(m/2)*P(x, n - m)], {m, 1, k}].at n=40A138094
- Coefficients of polynomials from matrix characteristic polynomials: m(n,m,d)=If[ m <= n, Mod[Binomial[n, m], 2], 0]; M(n)=m(n,m,d).Transpose[m(n,m,d)].Transpose[m(n,m,d)].m(n,m,d).at n=51A158202
- Omit first term of A160458 and divide by 5.at n=6A160459
- Number of ways to place 2 nonattacking nightriders on an n X n board.at n=12A172141
- Expansion of x*(1+2*x+8*x^2+4*x^3+3*x^4) / ( (1+x)^2*(x-1)^4 ).at n=25A178947
- Number of strings of numbers x(i=1..n) in 0..8 with sum i*x(i) equal to n*8.at n=6A184702
- Number of strings of numbers x(i=1..7) in 0..n with sum i*x(i) equal to n*7.at n=7A184707
- Number of nX2 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without consecutive moves in the same direction.at n=4A221870
- T(n,k)=Number of nXk arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without consecutive moves in the same direction.at n=16A221873
- T(n,k)=Number of nXk arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without consecutive moves in the same direction.at n=19A221873
- Numbers k such that k^3 - b2 is a triangular number (A000217), where b2 is the largest square less than k^3.at n=28A233401