10945
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14400
- Proper Divisor Sum (Aliquot Sum)
- 3455
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7920
- Möbius Function
- -1
- Radical
- 10945
- 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
- 42
- 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) = Fibonacci(n) - 1.at n=20A000071
- Möbius transform of A003965.at n=66A003980
- a(n) = Fibonacci(n) + (-1)^n.at n=21A008346
- "Pascal sweep" for k=10: draw a horizontal line through the 1 at C(k,0) in Pascal's triangle; rotate this line and record the sum of the numbers on it (excluding the initial 1).at n=31A009550
- Pseudoprimes to base 21.at n=25A020149
- Pisot sequence T(4,7).at n=16A020732
- Number of partitions of n in which the least part is 3.at n=55A026796
- a(n) = Fibonacci(2*n + 1) - 1.at n=10A027941
- Number of compositions (ordered partitions) of n into distinct odd parts.at n=49A032021
- Inverse Stolarsky array read by antidiagonals.at n=54A035507
- Fibocyclotomic numbers: numbers formed from cyclotomic polynomials and Fibonacci numbers (A000045).at n=46A051258
- a(n) = Fibonacci(n+2) - (1-(-1)^n)/2.at n=19A052952
- Third column of triangle A054450 (partial row sums of unsigned Chebyshev triangle A049310).at n=18A054451
- Numbers that are Fibonacci numbers plus or minus 1.at n=36A061489
- a(n) is the first of a triple of consecutive integers, each of which is the product of three distinct primes.at n=22A066509
- a(n) = Fibonacci(n+1) - (1 + (-1)^n)/2.at n=20A074331
- Sum of numbers that can be written as t*n + u*(n+1) for nonnegative integers t,u in exactly one way.at n=9A076454
- Odd terms in A027941.at n=3A076684
- n for which there is a chain (or permutation) of the numbers from 1 to n for which each adjacent pair sums to a Fibonacci number.at n=36A079734
- a(n) = Fibonacci(4n+1) - 1, or Fibonacci(2n)*Lucas(2n+1).at n=5A081007