5169
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 6896
- Proper Divisor Sum (Aliquot Sum)
- 1727
- 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
- 3444
- Möbius Function
- 1
- Radical
- 5169
- 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
- 54
- 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) = a(n-1) + a(n-2) - 1.at n=18A001588
- Expansion of e.g.f. tan(arcsin(arctan(x))) (odd powers only).at n=4A012089
- Expansion of e.g.f. exp(arctanh(arctan(x))).at n=9A012260
- From George Gilbert's marks problem: jumping 6 marks at a time (final positions).at n=10A019996
- Numbers k such that the continued fraction for sqrt(k) has period 70.at n=14A020409
- Numbers k that divide the (left) concatenation of all numbers <= k written in base 19 (most significant digit on left).at n=30A029488
- 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 46.at n=35A031544
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 32 ones.at n=30A031800
- Multiplicity of highest weight (or singular) vectors associated with character chi_28 of Monster module.at n=35A034416
- Number of partitions of n with equal number of parts congruent to each of 1, 3 and 4 (mod 5).at n=53A035580
- Number of partitions of n into parts not of the form 9k, 9k+2 or 9k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 3 are greater than 1.at n=40A035941
- a(n)=number of Gaussian integers z=a+bi satisfying |z|<=n+1/2.at n=40A036704
- a(1) = 8; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=33A046258
- Becomes prime or 4 after exactly 8 iterations of f(x) = sum of prime factors of x.at n=11A048130
- pi(n) associated with A049529.at n=6A049530
- a(n) = Sum_{i=0..n} T(i,n-i), array T as in A049687.at n=36A049688
- a(n) = Sum_{k=1..n} C(n, floor(n/k)).at n=14A051054
- Consider all integer triples (i,j,k), j >= k > 0, with binomial(i+2,3)=j^3+k^3, ordered by increasing i; sequence gives j values.at n=8A054206
- a(n) = a(n-1) + 2*a(floor(n/2)) if n > 0, otherwise 1.at n=22A058039
- Sum of divisors of twice square numbers.at n=40A065765