5193
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 7514
- Proper Divisor Sum (Aliquot Sum)
- 2321
- 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
- 1731
- Omega Function (Ω)
- 3
- 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
- 85
- 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
- Expansion of 1/Product_{m>=1} (1 - m*q^m)^27.at n=3A022751
- a(n) = least m such that if r and s in {1/1, 1/4, 1/7, ..., 1/(3n-2)} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=32A024836
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 16.at n=8A031694
- Numbers k such that 71*2^k+1 is prime.at n=15A032385
- Numbers whose set of base-8 digits is {1,2}.at n=38A032929
- Numbers having four 1's in base 8.at n=23A043428
- Numbers whose base-5 representation contains exactly two 1's and three 3's.at n=34A045243
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = a(3) = 3.at n=39A050065
- T(2n+4,n), array T as in A055216.at n=6A055220
- Table by antidiagonals of T(n,k) = 2*n*T(n,k-1) - n^2*T(n,k-2) + T(n,k-4) starting with T(n,1) = 1.at n=38A073135
- Interprimes which are of the form s*prime, s=9.at n=13A075284
- a(n) = 9*n^3 - 18*n^2 + 10*n.at n=9A086605
- Row sums of triangle A092683, in which the convolution of each row with {1,1} produces a triangle that, when flattened, equals the flattened form of A092683.at n=11A092685
- Expansion of 1/sqrt(1-6x-11x^2).at n=5A098444
- Triangle, read by rows, of the coefficients of [x^k] in G100225(x)^n such that the row sums are 3^n-1 for n>0, where G100225(x) is the g.f. of A100225.at n=53A100226
- Indices of primes in sequence defined by A(0) = 91, A(n) = 10*A(n-1) + 41 for n > 0.at n=16A101009
- a(n) = n*(20 + 15*n + n^2)/6.at n=26A101853
- Coefficients of the A-Rogers mod 14 identity.at n=33A105780
- Numbers n not divisible by 10 such that the decimal representation of n^26 does not use every nonzero digit.at n=21A112258
- Starting with 1, each number is the previous number plus the product of the index number and the sum of the digits of the previous number.at n=26A113904