6632
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 12450
- Proper Divisor Sum (Aliquot Sum)
- 5818
- 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
- 3312
- Möbius Function
- 0
- Radical
- 1658
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 2
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
- 93
- 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
- Numbers k such that Fib(k) == 21 (mod k).at n=42A023179
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 39.at n=31A031537
- Let (u1,u2) be successive untouchable numbers such that phi(u1) = phi(u2); sequence gives values of u2.at n=20A048190
- Numbers n such that 203*2^n-1 is prime.at n=10A050853
- a(n) = A000203(n)^2 - A001157(n) - 2n = sigma(n)^2 - sigma_2(n) - 2n.at n=41A066294
- Diagonal of triangular spiral in A051682.at n=38A081267
- a(n) = 3*n^2 + 6*n + 8.at n=46A106648
- Let f(n) = exp(Pi*sqrt(n)); sequence gives numbers n such that f(n) - floor(f(n)) < 1/10^3.at n=10A127028
- Conjecturally, even numbers n such that every even number greater than n has more decompositions as the sum of two primes.at n=41A174327
- 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=39A181299
- Number of nondecreasing strings of numbers x(i=1..7) in -n..n with sum x(i)^3 equal to 0.at n=20A188281
- Triangle of coefficients of polynomials u(n,x) jointly generated with A208762; see the Formula section.at n=41A208761
- Triangle of coefficients of polynomials u(n,x) jointly generated with A209696; see the Formula section.at n=42A209695
- Triangle of coefficients of polynomials u(n,x) jointly generated with A210228; see the Formula section.at n=52A210227
- Minimal number (in decimal representation) with n nonprime substrings in base-3 representation (substrings with leading zeros are considered to be nonprime).at n=36A217103
- Triangle T(n,k) by rows: number of ways k dominoes can be placed on an n X n chessboard, k>=0.at n=22A242861
- Number of 3-matchings of the n X n grid graph.at n=5A243206
- Numbers n such that integers n through n+6 and their squares all lack the digit 1 in their decimal expansion.at n=29A255431
- a(1) = 1; a(n+1) = Sum_{k=1..n} lcm(a(k),a(n))/a(n).at n=26A287006
- Expansion of g.f.: f'(t)/f(t), where f(t) = Sum_{p prime} t^p.at n=19A307977