15820
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 38304
- Proper Divisor Sum (Aliquot Sum)
- 22484
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5376
- Möbius Function
- 0
- Radical
- 7910
- Omega Function (Ω)
- 5
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 146
- 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
- Number of lines through exactly 5 points of an n X n grid of points.at n=48A018812
- Positive numbers k such that k and 5*k are anagrams in base 9 (written in base 9).at n=10A023082
- s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = (composite numbers).at n=39A025102
- a(n) = Sum_{k=1..n} lcm(n,k).at n=34A051193
- The minimal number which has multiplicative persistence 7 in base n.at n=9A064871
- Positions of powers of 2 in A064413.at n=14A064954
- a(n) = floor( {product of all possible sums of (n-1) numbers chosen from among first n numbers} / {sum of all possible products of (n-1) numbers chosen from among first n numbers} ).at n=5A093885
- G.f. satisfies: 24*A(x) = 23 + 64*x + A(x)^8, starting with [1,4,28].at n=4A120604
- a(n) = floor(((1+sqrt(3))/2)^n).at n=30A125895
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 1), (-1, 1, 0), (1, -1, -1), (1, 0, 0)}.at n=10A148517
- Sum of neighbor maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to the sum mod 4 of their horizontal and vertical neighbors in a random 0..3 nX2 array.at n=6A220801
- T(n,k)=Sum of neighbor maps: number of nXk binary arrays indicating the locations of corresponding elements equal to the sum mod 4 of their horizontal and vertical neighbors in a random 0..3 nXk array.at n=29A220805
- T(n,k)=Sum of neighbor maps: number of nXk binary arrays indicating the locations of corresponding elements equal to the sum mod 4 of their horizontal and vertical neighbors in a random 0..3 nXk array.at n=34A220805
- T(n,k)=Sum of neighbor maps: number of nXk binary arrays indicating the locations of corresponding elements equal to the sum mod 4 of their horizontal and antidiagonal neighbors in a random 0..3 nXk array.at n=29A222935
- Sum of neighbor maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to the sum mod 4 of their horizontal and antidiagonal neighbors in a random 0..3 2Xn array.at n=6A222936
- Triangular array read by rows. T(n,k) is the number of 2-colored labeled graphs on n nodes with exactly k edges; n >= 0, 0 <= k <= A002620(n).at n=38A228890
- Irregular triangular array read by rows: T(n,k) is the number of 2-colored simple labeled graphs on n nodes that have exactly k edges, 0<=k<=A002620(n), n>=1.at n=37A241669
- Irregular triangle read by rows: T(n,k) = number of size k subsets of S_n that remain unchanged under the operation of replacing a permutation with its inverse.at n=25A277081
- Irregular triangle read by rows: T(n,k) = number of size k subsets of S_n that remain unchanged under the operation of replacing a permutation with its inverse.at n=27A277081
- Ulam numbers u such that 5*u is also an Ulam number.at n=29A287613