15078
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
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 34560
- Proper Divisor Sum (Aliquot Sum)
- 19482
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4296
- Möbius Function
- 1
- Radical
- 15078
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 115
- 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
- yes
- Odd
- no
Appears in sequences
- Least positive integer coefficients of power series A(x) such that the coefficients of A(x)^2 + A(x) - 1 consist entirely of squares.at n=82A083352
- a(1) = 932; for n > 1, a(n) = a(n-1) + 1 + sum of distinct prime factors of a(n-1) that are < a(n-1).at n=37A105213
- This is to A139025 as A139025 to A014688, see A139025 for details.at n=24A139026
- a(n) = 686*n - 14.at n=21A157363
- Number of lines through at least 2 points of a 7 X n grid of points.at n=37A160847
- Number of binary strings of length n with no substrings equal to 0001 0101 or 1100.at n=16A164474
- Integers whose binary digits "1" define, if sorted into a quadrant shape whose right angle lies in a Go board corner, same colored Go stones that surely live all, but not if any stone is omitted.at n=29A166537
- a(n) = coefficient of x^n in the (n+1)-th iteration of (x + x^2 + x^3) for n>=1.at n=5A166883
- Expansion of (18*x+86*x^2)/(1-11*x^2-150*x^3).at n=5A250101
- G.f. A(x) satisfies: x = A(x)-3*A(x)^2-2*A(x)^3.at n=5A276315
- a(n) = A007678(2*n)/(2*n).at n=36A341734
- Sum of numbers of y-multisets of divisors of x for each x >= 1, y >= 0, x + y = n.at n=24A343661