12680
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 28620
- Proper Divisor Sum (Aliquot Sum)
- 15940
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5056
- Möbius Function
- 0
- Radical
- 3170
- Omega Function (Ω)
- 5
- 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
- 81
- 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) = Sum_{k=m..n} T(k,n-k), where m = floor((n+1)/2); a(n) is the n-th diagonal-sum of left justified array T given by A027935.at n=24A027947
- 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 55.at n=35A031553
- a(0)=0, a(1)=1, a(2)=1, a(3)=1, a(n) = a(n-3) + a(n-4) for n > 3.at n=50A079398
- Partial sums of A000960.at n=35A099074
- Triangle read by rows: T(n,k) is the number of Schroeder paths of length 2n and having k low humps.at n=37A101281
- Iccanobirt numbers (4 of 15): a(n) = R(a(n-1)) + a(n-2) + a(n-3), where R is the digit reversal function A004086.at n=17A102114
- n*(1+3*n+6*n^2)/2.at n=16A115519
- a(n) = n*(8*n - 3).at n=40A139273
- Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (-1, 0), (0, 1), (1, -1)}.at n=12A151385
- Partial sums of A005109.at n=22A172167
- Those positive integers n where, when written in binary, there are exactly k number of runs (of either 0's or 1's) each of exactly k length, for all k where 1<=k<=m, for some positive integer m.at n=17A175356
- Number of partitions of n containing the number of distinct parts as a part.at n=39A239945
- Number of partitions of n such that (number parts having multiplicity 1) is a part or (number of parts > 1) is a part.at n=36A241515
- Number of compositions of n such that the smallest part has multiplicity two.at n=16A241862
- Number of (n+1) X (5+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=5A253466
- 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=4A253467
- Number of (n+2)X(1+2) 0..1 arrays with every 3X3 subblock diagonal sum minus antidiagonal median nondecreasing horizontally and vertically.at n=2A253813
- Number of (n+2)X(3+2) 0..1 arrays with every 3X3 subblock diagonal sum minus antidiagonal median nondecreasing horizontally and vertically.at n=0A253815
- T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock diagonal sum minus antidiagonal median nondecreasing horizontally and vertically.at n=3A253820
- T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock diagonal sum minus antidiagonal median nondecreasing horizontally and vertically.at n=5A253820