4385
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 5268
- Proper Divisor Sum (Aliquot Sum)
- 883
- 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
- 3504
- Möbius Function
- 1
- Radical
- 4385
- 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
- 139
- 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
- a(n) = floor(tau*a(n-1)) + a(n-2) with a(0)=0 and a(1)=2.at n=12A005829
- Coordination sequence T2 for Zeolite Code RTH.at n=46A009894
- Numbers k such that the continued fraction for sqrt(k) has period 23.at n=14A020362
- Numbers whose set of base-16 digits is {1,2}.at n=16A032936
- Numbers whose base-4 representation has exactly 7 runs.at n=9A043598
- Numbers k such that number of runs in the base 4 representation of k is congruent to 1 mod 6.at n=27A043838
- Numbers n such that number of runs in the base 4 representation of n is congruent to 0 mod 7.at n=9A043843
- Numbers n such that number of runs in the base 4 representation of n is congruent to 7 mod 8.at n=9A043857
- Numbers n such that number of runs in the base 4 representation of n is congruent to 7 mod 9.at n=9A043865
- Numbers k such that the number of runs in the base-4 representation of k is congruent to 7 (mod 10).at n=9A043874
- Numbers whose base-5 representation contains exactly three 0's and two 2's.at n=11A045186
- Numbers n such that 225*2^n-1 is prime.at n=12A050864
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 21.at n=7A051986
- Numbers k such that 4^k - 3 is prime.at n=22A059266
- Numerator of the n-th convergent to Sum_{k>=0} 1/2^(2^k).at n=7A073414
- Formed from a secondary diagonal of triangle A096542 where a(n) = A096542(n,n-3)/4.at n=5A096544
- a(n) = n^3 + (n+1)^2.at n=16A100705
- Numbers k such that phi(k) + prime(k) is a triangular number.at n=22A115908
- The second of the pair of consecutive integers k and k+1 such that sopfr(k) divides sopfr(k+1), where sopfr(k) is the sum of the prime factors of k, counting multiplicity.at n=38A129317
- Positions of 16 after decimal point in decimal expansion of Pi.at n=42A134216