15888
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 41168
- Proper Divisor Sum (Aliquot Sum)
- 25280
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5280
- Möbius Function
- 0
- Radical
- 1986
- Omega Function (Ω)
- 6
- 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
- 97
- 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
- a(n) = n*(31*n + 1)/2.at n=32A022289
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 21.at n=5A031699
- Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 2,0,1,3.at n=5A037718
- Starting positions of strings of three 6's in the decimal expansion of Pi.at n=10A083625
- Numbers k such that the k-th triangular number contains only digits {1,2,6}.at n=15A119104
- Number of partitions of n such that number of odd parts is greater than or equal to number of even parts.at n=37A130780
- Numbers k such that k and k^2 use only the digits 1, 2, 4, 5 and 8.at n=21A136990
- a(1) = 1, a(2) = 2, a(n+2) = 2*a(n+1) + (n + 1)*(n + 2)*a(n).at n=6A142983
- a(n) = 512n + 16.at n=30A157475
- a(n) = 441n^2 + 2n.at n=5A158321
- Number of partitions of n such that the number of parts and the greatest part are coprime.at n=37A200750
- Number of (n+1) X (2+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.at n=5A253463
- Number of (n+1) X (6+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.at n=1A253467
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every 2X2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.at n=22A253468
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every 2X2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.at n=26A253468
- Least positive integer k such that prime(k)-k, prime(k)+k, prime(k*n)-k*n, prime(k*n)+k*n, prime(k)+k*n and prime(k*n)+k are all prime.at n=33A259492
- Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00001011 00010101 or 01010101.at n=8A261375
- Number of non-equivalent ways to tile an n X n X n triangular area with three 2 X 2 X 2 triangular tiles and an appropriate number (= n^2-12) of 1 X 1 X 1 tiles.at n=8A286445
- Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 302", based on the 5-celled von Neumann neighborhood.at n=41A287541
- Smallest m such that A357477(m) = n.at n=25A357675