13002
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 6
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 28512
- Proper Divisor Sum (Aliquot Sum)
- 15510
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3920
- Möbius Function
- 1
- Radical
- 13002
- 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
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 138
- 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
- Positive numbers k such that k and 2*k are anagrams in base 4 (written in base 4).at n=26A023059
- T(n,1) + T(n,2) + ... T(n,n), where T is the array in A026098.at n=26A026101
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 38.at n=5A031716
- Number of partitions of n with equal number of parts congruent to each of 3 and 4 (mod 5).at n=43A035561
- Half the number of 4 X n binary arrays with no path of adjacent 1's or adjacent 0's from top row to bottom row.at n=3A069430
- Half the number of n X 4 binary arrays with no path of adjacent 1's or adjacent 0's from top row to bottom row.at n=3A069442
- 4-Smith numbers.at n=11A103125
- a(n) = 2*n*(6*n-1).at n=33A126964
- Triangle, read by rows, where g.f.: A(x,y) = exp( Sum_{n>=1} (2^n + y)^n * x^n/n ) is a power series in x and y with integer coefficients.at n=25A155810
- a(n) = 36*n^2 + 6.at n=18A158479
- Averages of twin prime pairs which are a sum of averages of two consecutive twin prime pairs.at n=29A160916
- Sum of the numbers already removed (including the target number) in the first jump of a Sieve of Eratosthenes table.at n=26A179654
- Number of permutations of the n*(n+1)/2 numbers (i copies of i | i=1..n), with no element equal to another within a distance of 2.at n=4A190946
- Number of permutations of the n*(n+1)/2 numbers (i copies of i | i=1..n), with no element equal to another within a distance of 3.at n=5A190947
- Number of tilings of a 5 X n rectangle using n pentominoes of shapes W, I, L.at n=10A257866
- Total number of tilings of Ferrers-Young diagrams using dominoes and monominoes summed over all partitions of n.at n=11A304677
- 6*a(n) are the perimeters of distinct triangles with integer sides i <= j <= k, whose area equals 7 times their perimeter. Terms occurring more than once belong to different triangles.at n=79A332927
- Always start on the lowest digit of a(n), then visit all digits of a(n) in increasing order. The terms of the sequence are the smallest one that force the visitor to walk n steps to complete his tour (a single step drives you from a digit to the closest one).at n=9A336611
- Numbers of the form prime(i-1)+prime(i+1) that are the average of a twin prime pair.at n=45A342993
- Products of four distinct primes between twin primes.at n=35A353022