8426
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
- 5
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13824
- Proper Divisor Sum (Aliquot Sum)
- 5398
- 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
- 3820
- Möbius Function
- -1
- Radical
- 8426
- 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
- 83
- 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
- a(0) = 1, a(n) = 26*n^2 + 2 for n>0.at n=18A010016
- Numbers whose sum of divisors is a cube.at n=44A020477
- a(n) = [ C(2n,n)/2^(n+3) ].at n=19A024506
- a(n) = Sum_{k=0..n} (k+1) * A026736(n,n-k).at n=10A027220
- Numbers whose base-4 representation contains exactly two 0's and four 2's.at n=32A045051
- a(n) = 3*trinomial(n+1,0) - trinomial(n+2,0).at n=11A103872
- a(0)=1, a(1)=2, a(2)=3, a(3)=5, a(4)=7, a(5)=10; a(n) = floor(a(n-1) + 1 + (a(n-2) + 1)/6) for n>=6.at n=52A119592
- Partial sums of skinny numbers (A061909).at n=39A130596
- Number of binary strings of length n with no substrings equal to 0001 or 0101.at n=16A164395
- Numbers k such that 12*k - 5, 12*k - 1, 12*k + 1, and 12*k + 5 are primes.at n=38A174372
- 1/4 the number of (n+1) X 7 binary arrays with all 2 X 2 subblock sums the same.at n=13A183983
- Numbers n such that d(n-1) = d(n+1) = 6, where d(k) is the number of divisors of k (A000005).at n=31A190267
- Triangle of coefficients of polynomials v(n,x) jointly generated with A210233; see the Formula section.at n=50A210234
- Number of (n+1)X(5+1) 0..3 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with values 0..3 introduced in row major order.at n=3A231461
- T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with values 0..3 introduced in row major order.at n=31A231463
- Number of (4+1)X(n+1) 0..3 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with values 0..3 introduced in row major order.at n=4A231467
- Number of nX3 0..3 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors.at n=2A231936
- T(n,k)=Number of nXk 0..3 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors.at n=12A231940
- Number of 3Xn 0..3 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors.at n=2A231942
- Nonnegative integers n such that in balanced ternary representation the number of occurrences of each trit doubles when n is squared.at n=14A257867