10919
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11160
- Proper Divisor Sum (Aliquot Sum)
- 241
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10680
- Möbius Function
- 1
- Radical
- 10919
- 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
- 174
- 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
- Erroneous version of A047709.at n=10A002911
- a(n) = ((n+1)-st Fibonacci number) - (n-th non-Fibonacci number).at n=19A014241
- Numbers k such that sopfr(k) = sopfr(k - sopfr(k)).at n=18A050781
- Row sums of array T as in A054110.at n=12A054111
- Odd numbers n for which 17 is the smallest i (>= 1) with Jacobi symbol J(i,n) getting either a value 0 or -1.at n=10A112077
- Semiprimes n such that 3*n + 4 is a square.at n=22A112666
- a(0) = 3, a(1) = 5, a(2) = 1, and a(n) = (2^(1 + n) - 11*(-1)^n)/3 for n > 2.at n=14A115335
- Smallest number k such that k^n is equal to the sum of n consecutive primes, or 1 if it does not exist.at n=30A123112
- a(n) = 4*n^2 - 6*n + 1.at n=52A125202
- Record values in A046641.at n=32A145771
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (0, 1, 1), (1, 0, 1), (1, 1, -1)}.at n=7A150654
- a(n) = (2*n+1)*(6*n-1).at n=30A179741
- Sum of tail length of S over all 2^n strings S consisting of n 2's and 3's.at n=11A216813
- Sum of products of elements of nonempty subsets of divisors of n.at n=11A229337
- Number of partitions of n into parts > 0 without 1 as digit, cf. A052383.at n=53A248518
- G.f.: Product_{k>=1} 1/(1-x^k)^Fibonacci(k+2).at n=11A260787
- Define Z(1) = {1}, and Z(n+1) = Z(n) (+) { x+y, with x and y in Z(n) } for any n>0 (where (+) stands for the symmetric difference of two sets). Then a(n) gives the number of elements in Z(n).at n=14A263402
- Indices of record values in A266948: least prime p such that p-2 and 6n-p are also prime.at n=12A266950
- Positions of records in A329656.at n=14A329657
- a(n) + a(n+1) = 2^n for n >= 0 with a(0) = 4.at n=15A352692