13015
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 16560
- Proper Divisor Sum (Aliquot Sum)
- 3545
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9792
- Möbius Function
- -1
- Radical
- 13015
- 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
- 50
- 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
- Number of paraffins.at n=36A005997
- McKay-Thompson series of class 6A for Monster.at n=6A007254
- dot_product(n,n-1,...2,1)*(6,7,...,n,1,2,3,4,5).at n=32A026063
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 12.at n=19A031690
- McKay-Thompson series of class 6A for Monster.at n=6A045484
- a(n) = n*(2*n^2 - 2*n + 1).at n=19A059722
- Expansion of (1 - x - x^2 - sqrt(1 - 2*x - 5*x^2 - 2*x^3 + x^4)) / (2*x + 2*x^2).at n=11A078481
- Triangle read by rows: T(n,k) is number of Dyck paths of semilength n and having k UDUD's (here U=(1,1), D=(1,-1)).at n=56A094507
- Riordan array (1/((1-x)(1-3x)),x/((1-x)(1-3x))).at n=40A116414
- Numbers n such that the sum of the first n odd composites is palindromic in base 2.at n=11A118128
- a(n) = ceiling(n/2)*ceiling(n^2/2).at n=37A131474
- Integers k such that 10^k + 73 is a prime number.at n=9A135132
- a(n) = 36*n^2 + n.at n=18A157324
- a(n) = 361*n^2 + 19.at n=6A158592
- Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2>x^2+y^2.at n=37A211637
- Triangle read by rows: T(n,k) is the number of permutations of{1,2,...,n} avoiding [x,x+1] having genus k (see first comment for definition of genus).at n=55A218538
- Triangular array read by rows: row n shows the coefficients of the polynomial u(n) = c(0) + c(1)*x + ... + c(n)*x^(n) which is the numerator of the n-th convergent of the continued fraction [k, k, k, ... ], where k = (x + 1)/(x + 2).at n=37A231774
- Number of n X 4 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.at n=6A252816
- Number of nX7 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.at n=3A252819
- T(n,k)=Number of nXk nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.at n=48A252820