15016
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 28170
- Proper Divisor Sum (Aliquot Sum)
- 13154
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7504
- Möbius Function
- 0
- Radical
- 3754
- Omega Function (Ω)
- 4
- 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
- 27
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- 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 61.at n=27A031559
- Row sums of signed triangle A056588.at n=8A056592
- Smallest x > 1 such that x^prime(n) == 1 mod(prime(i)) 2<=i<=n.at n=4A071554
- Numbers k such that 2^(2*k+1) + 2^k + 1 is prime.at n=37A105180
- Expansion of q / (chi(-q) * chi(-q^3) * chi(-q^5) * chi(-q^15)) in powers of q where chi() is a Ramanujan theta function.at n=42A123632
- Series reversion of x/(1 + x + x^4).at n=14A127902
- a(n) = number of bits in the binary expansion of A046967(n).at n=5A135249
- Number of 1's in all compositions of n into odd parts.at n=18A239342
- Number of nonnegative integers with property that their base 8/3 expansion (see A024645) has n digits.at n=8A245419
- Centered heptagonal numbers (A069099) which are also centered pentagonal numbers (A005891).at n=2A253622
- Wiener index of the n X n black bishop graph.at n=15A292051
- Wiener index of the n X n white bishop graph.at n=14A292059
- The Riordan square of the Euler numbers. Triangle T(n, k), 0 <= k <= n, read by rows.at n=41A321630
- Number of rectangular plane partitions of n with strictly decreasing rows and columns.at n=43A323430
- a(n) = A276156(n) / A002110(A007814(n)).at n=65A328461
- Row 2 of A328464: a(n) = A276156(4n - 2) / 2.at n=16A328465
- Expansion of g.f. A(x) satisfying A(x) = x*(1 + A(x))/(1 - x*(x + A(x))/(1 - x*(x^2 + A(x))/(1 - x*(x^3 + A(x))/(1 - ...)))), a continued fraction.at n=10A369530
- Triangle read by rows: T(n,k) = (A002110(n) + A002110(k)) / A002110(k), 1 <= k <= n.at n=15A370135
- G.f. A(x,y) satisfies 1/x = Sum_{n=-oo..+oo} A(x,y)^n * (A(x,y)^n + y)^(n+1), as a triangle of coefficients T(n,k) of x^n*y^k in A(x,y), read by rows.at n=38A379200
- G.f. A(x) satisfies A(x)^4 = A( A(x)^3 * x/(1-x) ).at n=14A380554