4148
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
- 12
- Divisor Sum
- 7812
- Proper Divisor Sum (Aliquot Sum)
- 3664
- 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
- 1920
- Möbius Function
- 0
- Radical
- 2074
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 126
- 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
- Number of switching networks (see Harrison reference for precise definition).at n=2A000836
- Hit polynomials; convolution of natural numbers with Fibonacci numbers F(2), F(3), F(4), ....at n=14A001891
- Numbers k such that sigma(k+2) = sigma(k).at n=12A007373
- a(n) = c(prime(n))/prime(n), where c = Perrin sequence A001608 (starting 0,2,3,...) and prime(n) is the n-th prime.at n=13A014981
- Inverse Euler transform of A000931.at n=42A018243
- Numbers k such that Fib(k) == 21 (mod k).at n=28A023179
- 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 32.at n=32A031530
- Concatenation of n and n+7.at n=40A032612
- Numbers whose set of base-11 digits is {1,3}.at n=24A032918
- Number of partitions in parts not of the form 7k, 7k+2 or 7k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 2 are greater than 1.at n=45A035938
- Schoenheim bound L_1(n,4,3).at n=43A036831
- Number of partitions satisfying cn(2,5) <= cn(1,5) + cn(4,5) and cn(3,5) <= cn(1,5) + cn(4,5).at n=29A039891
- Denominators of continued fraction convergents to sqrt(206).at n=7A041383
- Denominators of continued fraction convergents to sqrt(811).at n=10A042565
- Numbers whose base-16 representation has exactly 4 runs.at n=33A043677
- Numbers whose base-4 representation contains exactly four 0's and two 1's.at n=16A045035
- Numbers whose base-4 representation contains exactly four 0's and no 2's.at n=32A045057
- Numbers whose base-4 representation contains exactly four 0's and one 3.at n=31A045082
- Write fundamental unit for real quadratic field of discriminant n as x + y*omega; sequence gives values of y for n == 2 mod 4.at n=42A053374
- Iteration of unitary-sigma function: a(1) = 2, a(n) = usigma(a(n-1)).at n=18A059460