13571
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13944
- Proper Divisor Sum (Aliquot Sum)
- 373
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13200
- Möbius Function
- 1
- Radical
- 13571
- 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
- 89
- 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
- Numbers k such that 221*2^k+1 is prime.at n=32A032487
- Numerators of b(n) = (1/16^n)*(4/(8*n+1) - 2/(8*n+4) - 1/(8*n+5) - 1/(8*n+6)).at n=33A048581
- Smallest number m such that exactly n odd numbers can be seen as proper subsequences of m in decimal representation.at n=29A164766
- Wiener index of the n-pan graph.at n=46A180861
- Number of nondecreasing arrangements of 6 numbers x(i) in -(n+4)..(n+4) with the sum of sign(x(i))*2^|x(i)| zero.at n=32A187990
- a(n) is the sum of all distinct integers that can be produced by reversing the digits of n in any base b >= 2.at n=51A211518
- Number of nX3 0..4 arrays with no three equal values in a row horizontally or vertically, and new values 0..4 introduced in row major order.at n=2A222921
- T(n,k)=Number of nXk 0..4 arrays with no three equal values in a row horizontally or vertically, and new values 0..4 introduced in row major order.at n=12A222924
- Composites c where at least one base b with 1 < b < c exists such that b^(c-1) == 1 (mod c^2), i.e., composites c that are base-b 'Wieferich pseudoprimes' for at least one b between 1 and c.at n=35A267288
- Number of integer partitions of n whose run-lengths are either weakly increasing or weakly decreasing.at n=39A332745
- a(n) = A337339(n) - n.at n=41A337341
- Setwise difference A340150 \ A340076.at n=30A340151
- a(n) = (2*n^3 - n^2 + 3*n - 2)/2.at n=23A363288