4445
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
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 6144
- Proper Divisor Sum (Aliquot Sum)
- 1699
- 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
- 3024
- Möbius Function
- -1
- Radical
- 4445
- 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
- 33
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = n concatenated with n + 1.at n=43A001704
- a(n) = 3*n^2 + 3*n - 1.at n=38A004538
- Kaprekar triples: q such that q = x + y + z and q^3 = x*10^2n + y*10^n + z, where z < 10^n and n is the number of digits in q. q is not a power of 10 (except q=1).at n=6A006887
- From a problem in AI planning: a(n) = 4+a(n-1)+a(n-2)+a(n-3)+a(n-4)-a(n-5)-a(n-6)-a(n-7), n>7.at n=13A007800
- Coordination sequence T1 for Zeolite Code AFI.at n=46A008014
- Coordination sequence T4 for Zeolite Code RUT.at n=44A009900
- Coordination sequence T3 for Zeolite Code VNI.at n=41A009909
- Four-fold exponential convolution of Fibonacci numbers with themselves (divided by 24).at n=8A014341
- Numbers that are the sum of 4 distinct positive cubes in 3 or more ways.at n=15A025413
- Least sum of 4 distinct positive cubes in exactly n ways.at n=3A025421
- a(n) = Sum_{0<=j<=i<=n} A027157(i, j).at n=8A027166
- Pair up the numbers.at n=22A030656
- Numbers having three 4's in base 10.at n=16A043507
- Numbers n > 9 such that x^n + x^9 + x^8 + x^7 + x^6 + x^5 + x^4 + x^3 + x^2 + x +1 is irreducible over GF(2).at n=19A057487
- Pseudo-Kaprekar triples: q such that if q=x+y+z, then q^3=x*10^i + y*10^j + z, where (y*10^j+z < 10^i) and z < 10^j.at n=16A060768
- Erroneous version of A006887.at n=7A060809
- Square array read by antidiagonals of number of length 2k walks on an n-dimensional hypercubic lattice starting and finishing at the origin and staying in the nonnegative part.at n=62A064045
- Number of length 6 walks on an n-dimensional hypercubic lattice starting and finishing at the origin and staying in the nonnegative part.at n=7A064046
- Four-digit numbers that do not resolve to 6174 under the Kaprekar map (see A151949).at n=32A069746
- Let u(1)=1, u(n)=2^u(n-1) (mod n), sequence gives values of n such that u(n)=1.at n=43A076825