13126
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19692
- Proper Divisor Sum (Aliquot Sum)
- 6566
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6562
- Möbius Function
- 1
- Radical
- 13126
- Omega Function (Ω)
- 2
- 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
- 76
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Numbers that are the sum of 6 nonzero 8th powers.at n=13A003384
- Difference between the arithmetic mean of the neighbors of the terms and the term itself follows the pattern 0,1,2,3,4,5,...at n=35A086514
- Number of idempotent order-preserving partial transformations (of an n-element chain).at n=8A112091
- Numerator of the polynomial A_l(x) = Sum_{d=1..l-1} x^(l-d)/d for index l=2n+1 evaluated at x=8.at n=1A145623
- Indices in A146326 where records occur.at n=46A146345
- 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, 0), (-1, 1, 1), (0, 0, 1), (1, 0, -1)}.at n=10A148296
- a(n) = 625*n + 1.at n=20A158383
- a(n) = 6+32*n^2+8*n*(7+8*n^2)/3.at n=8A167498
- Smallest number k such that the continued fraction expansion of sqrt(k) contains n distinct numbers.at n=24A187142
- Numbers k such that the periodic part of the continued fraction of sqrt(k) has more ones than any smaller k.at n=28A206579
- a(n+3) = -a(n+2) + 2a(n+1) + a(n) with a(0)=-1, a(1)=0, a(2)=-3.at n=17A214683
- Total number of parts of multiplicity 7 in all partitions of n.at n=41A222707
- Sum of the third largest parts in the partitions of n into 8 parts.at n=38A308996
- a(n) is the smallest number that is the sum of n positive 6th powers in two ways.at n=19A343079
- a(n) is the Wiener index of a tridon on n vertices.at n=38A349418
- Indices of records in A028832.at n=25A374232
- Numbers k such that k - sopfr(k) is a positive fourth power.at n=6A390141