8549
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8736
- Proper Divisor Sum (Aliquot Sum)
- 187
- 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
- 8364
- Möbius Function
- 1
- Radical
- 8549
- Omega Function (Ω)
- 2
- 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
- 65
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Natural numbers exponentiated twice.at n=5A007550
- a(n) is the smallest composite number c such that A002110(n) + c is prime.at n=22A038771
- Numerators of continued fraction convergents to sqrt(201).at n=8A041372
- "Canada perfect numbers": n such that the sum of digits^2 of n equals the sum of d|n, 1<d<n.at n=2A070308
- a(n) is the largest number such that all of a(n)'s length-n substrings are distinct and divisible by 61.at n=2A093261
- Numbers n such that A001414(n) = sum of squared digits of n.at n=17A094908
- Triangle read by rows: coefficient of x^n in the power series of x/(1 - m*x - x^2 + x^3 - x^5) in row n, column m=1..n+2.at n=33A117744
- G.f.s of the z^p coefficients of the polynomials in the GF2 denominators of A156925.at n=25A157703
- G.f.s of the z^p coefficients of the polynomials in the GF2 denominators of A156925.at n=34A157703
- a(n) = 225*n - 1.at n=37A158227
- a(n) = 38*n^2 - 1.at n=14A158596
- Square array A(n,k), n>=0, k>=0, read by antidiagonals, A(n,k) = exponential transform applied n times to identity function, evaluated at k.at n=42A209631
- Smallest k > 0 such that (5^n+k)*5^n-1 and (5^n+k)*5^n+1 are a twin prime pair.at n=37A212487
- Numbers n such that sum of squares of digits of n equals the sum of prime divisors of n.at n=20A217390
- Floor(1/s(n)), where s(n) = (2n+1)/(2n+2) - n*log((n+1)/n).at n=36A227721
- Number of unlabeled rooted trees with n nodes and maximal outdegree (branching factor) 4.at n=9A244400
- Semiprimes whose prime factors are of equal binary length and which differ from each other in exactly three bit positions.at n=21A261075
- Number of set partitions C'_t(n) of {1,2,...,t} into at most n parts, with an even number of elements in each part distinguished by marks and such that no part contains both 1 and t (each unmarked) or both i and i+1 (each unmarked) for some i with 1 <= i < t; triangle C'_t(n), t>=0, 0<=n<=t, read by rows.at n=39A261319
- Numbers whose arithmetic derivative is equal to the sum of some fixed power of their digits.at n=7A269719
- Expansion of A(x) = 1 + x + x*A(x) + x^2*A(x)^2 + x^3*A(x)^3.at n=9A304121