13917
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18560
- Proper Divisor Sum (Aliquot Sum)
- 4643
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9276
- Möbius Function
- 1
- Radical
- 13917
- 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
- 58
- 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
- a(n) = a(n-1) + a(n-6), with a(i) = 1 for i = 0..5.at n=41A005708
- Expansion of 1/(1 - x^6 - x^7 - x^8 - ...).at n=47A017900
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 78.at n=35A031576
- Composite numbers k such that k!/k# + 1 is prime, where k# = primorial numbers A034386.at n=21A049420
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 18.at n=52A050967
- Main diagonal of A099239.at n=6A099240
- (6n+5)-th terms of expansion of 1/(1 - x - x^6).at n=6A099242
- Numbers k such that k!/k# + 1 is prime, where k# is the primorial function (A034386).at n=28A140294
- Triangle T(n, k, j) = T(n-1, k, j) + T(n-1, k-1, j) + (2*j + 1)*prime(j)*T(n-2, k-1, j) with T(2, k, j) = prime(j) and j = 9, read by rows.at n=16A153654
- Triangle T(n, k, j) = T(n-1, k, j) + T(n-1, k-1, j) + (2*j + 1)*prime(j)*T(n-2, k-1, j) with T(2, k, j) = prime(j) and j = 9, read by rows.at n=19A153654
- Number of isomorphism classes of nanocones with 3 pentagons and a nearsymmetric boundary of length n.at n=33A198014
- Number of (n+2)X(7+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 4 6 or 7.at n=0A252557
- T(n,k) = Number of (n+2) X (k+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 1 2 4 6 or 7.at n=21A252558
- Number of (1+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 4 6 or 7.at n=6A252559
- Number of (n+1) X (2+1) 0..1 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal maximum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=4A253344
- T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every 2X2 subblock diagonal maximum minus antidiagonal maximum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=19A253350
- Number of (5+1)X(n+1) 0..1 arrays with every 2X2 subblock diagonal maximum minus antidiagonal maximum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=1A253354
- G.f. A(x) satisfies: A(x)^2 = A( x^2*(1+x)/(1-x) ), with A(0) = 0.at n=16A259117
- Ulam numbers k such that 4*k and 16*k are also Ulam numbers.at n=20A287634
- Expansion of Product_{k>=1} (1 + (1 + x + x^2) * x^k).at n=29A309173