13191
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17592
- Proper Divisor Sum (Aliquot Sum)
- 4401
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8792
- Möbius Function
- 1
- Radical
- 13191
- 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
- 125
- 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
- Number of P-graphs with vertical symmetry.at n=7A007163
- Convolution of (F(2), F(3), F(4), ...) and primes.at n=14A023657
- a(n) = Sum_{k=0..floor(n/2)} A026637(n, k).at n=14A026645
- Multiplicity of highest weight (or singular) vectors associated with character chi_66 of Monster module.at n=39A034454
- Positions in A181391 where the terms listed in A171863 appear.at n=20A171864
- Partial sums of A034897.at n=11A174226
- Partial sums of A079062.at n=31A177455
- Parameters n for which the elliptic curve y^2=x^3+n has rank 4.at n=15A179124
- Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 2..n-2.at n=7A180830
- Strings of 5 digits from 1...9, such that no formula using the single digits in the given order exists that evaluates to 0.at n=4A288355
- Index of the first occurrence of n-th prime in Van Eck's sequence (A181391), or 0 if n-th prime never appears.at n=53A357908
- Number of conjugacy classes of subgroups of the group GL(2, Z_n) of invertible 2 X 2 matrices mod n.at n=38A364921
- a(n) is the first position where the digits of n occur simultaneously in the decimal expansions of Pi and e.at n=49A381980