8122
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 12672
- Proper Divisor Sum (Aliquot Sum)
- 4550
- 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
- 3900
- Möbius Function
- -1
- Radical
- 8122
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 39
- 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
- Numbers k such that the continued fraction for sqrt(k) has period 70.at n=27A020409
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = A000201 (lower Wythoff sequence), t = A001950 (upper Wythoff sequence).at n=27A024686
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = A000201 (lower Wythoff sequence), t = A001950 (upper Wythoff sequence).at n=26A025119
- Numbers k that divide the (right) concatenation of all numbers <= k written in base 2 (most significant digit on left).at n=32A029447
- (s(n)+2)/10, where s(n)=n-th base 10 palindrome that starts with 8.at n=34A043087
- Numbers whose base-5 representation contains exactly three 2's and three 4's.at n=3A045292
- Number of oriented trees rooted at an arc.at n=6A063881
- Rounded volume of a regular tetrahedron with edge length n.at n=41A071399
- Least nontrivial multiple of the n-th prime beginning with 8.at n=31A078292
- Triangular matrix, read by rows, that satisfies: T(n,k) = [T^2](n-1,k) when n>k>=0, with T(n,n) = (2*n+1).at n=15A102320
- Column 0 of triangular matrix A102320, which satisfies T(n,k) = [T^2](n-1,k) when n>k>=0, with T(n,n) = (2*n+1).at n=5A102321
- Triangle, read by rows, where T(n,k) = T(n,k-1) + (2*k+1)*T(n-1,k) for n>k>0, T(n,0)=1 and T(n,n) = T(n,n-1) for n>=0.at n=19A102323
- Triangle, read by rows, where T(n,k) = T(n,k-1) + (2*k+1)*T(n-1,k) for n>k>0, T(n,0)=1 and T(n,n) = T(n,n-1) for n>=0.at n=20A102323
- Triangle, read by rows, equal to the matrix square of A113983.at n=45A113988
- Column 0 of triangle A113988, which is the matrix square of A113983: a(n) = [A113983^2](n,0).at n=9A113989
- Triangle, read by rows, where column k equals column 0 of A113983^(k+1): T(n,k) = [A113983^(k+1)](n-k,0) for n>=k>=0.at n=56A113993
- Start with 1 and repeatedly reverse the digits and add 35 to get the next term.at n=33A118632
- Floor of sum of the first n^2 square roots.at n=23A138357
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, -1, 1), (0, 1, 0), (1, 0, -1)}.at n=10A148109
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (0, -1, -1), (1, 1, 1)}.at n=9A149077