6885
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 13068
- Proper Divisor Sum (Aliquot Sum)
- 6183
- 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
- 3456
- Möbius Function
- 0
- Radical
- 255
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 57
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = (4*n+1)*(4*n+5).at n=20A003185
- a(n) = Sum_{k=0..5} binomial(n,k).at n=16A006261
- a(n) is least k such that k and 6k are anagrams in base n (written in base 10).at n=9A023098
- Reverse and add (in binary) - written in base 10.at n=16A035522
- Number of degree-n irreducible polynomials over GF(2) with trace = 0 and subtrace = 0.at n=18A042980
- Number of degree-n irreducible polynomials over GF(2) with trace = 1 and subtrace = 1.at n=18A042982
- Numbers having three 0's in base 9.at n=27A043455
- Row sums of convolution triangle A030526.at n=4A045624
- Odd numbers divisible by exactly 6 primes (counted with multiplicity).at n=18A046319
- Generalized Stirling number triangle of the first kind.at n=18A051231
- Number of trees with n nodes and 4 leaves.at n=31A055291
- Numbers k such that 3*13^k + 2 is prime.at n=15A057871
- Numbers of the form (10*a + b)^2 + (10*b + a)^2 with a and b less than 10, in numerical order.at n=31A061191
- Numbers k such that tau_3(k) (the number of ordered factorizations of k as k = r*s*t) divides k.at n=31A069147
- Numbers k such that gcd(k, reverse(k)) = 27 = 3^3, where reverse(x) = A004086(x).at n=15A072016
- Number of binary Lyndon words of length n with trace 0 and subtrace 0 over Z_2.at n=18A074027
- Number of binary Lyndon words of length n with trace 1 and subtrace 1 over Z_2.at n=18A074030
- Number of reachable arrangements of coins in the game Blet starting with 2n coins.at n=6A075273
- a(n) = (2*n+5)*(2*n+1).at n=40A078371
- a(n) = n-th multiple of n with digit sum n.at n=26A082260