13020
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
- 48
- Divisor Sum
- 43008
- Proper Divisor Sum (Aliquot Sum)
- 29988
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2880
- Möbius Function
- 0
- Radical
- 6510
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 5
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
- 76
- 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 ways in which n identical balls can be distributed among 4 boxes in a row such that each pair of adjacent boxes contains at least 4 balls.at n=34A005337
- Number of n-step walks on square lattice in the first quadrant which finish at distance n-3 from the x-axis.at n=27A005564
- Number of tree-rooted planar maps with 4 faces and n vertices and no isthmuses.at n=4A006471
- Positive numbers k such that k and 2*k are anagrams in base 4 (written in base 4).at n=27A023059
- a(n+1) = a(n) converted to base 10 from base 5 (written in base 10).at n=6A023383
- Perimeters of more than one primitive Pythagorean triangle.at n=20A024408
- Numbers whose base-5 representation contains exactly three 0's and three 4's.at n=4A045217
- Numbers k such that sigma (x) = k has exactly 11 solutions.at n=15A060678
- a(n)=Sum_{d|n} d*numbpart(d), where numbpart(d)=number of partitions of d, cf. A000041.at n=19A061259
- Numbers k such that k^6 + 1091 is prime.at n=7A066386
- Numbers k such that the sum over the prime divisors of k equals the number of divisors of k.at n=39A069234
- a(n) = lcm_{d|n} sigma(d).at n=47A069934
- Numbers k such that the sign of core(k)-phi(k) is not equal to 2*mu(k)^2-1, where core(k) is the squarefree part of k.at n=19A070237
- Group successively larger composite numbers so that the sum of the n-th group is a multiple of n. Sequence gives the sum of the terms in the n-th group.at n=34A074120
- Numbers whose set of base 5 digits is {0,4}.at n=42A097251
- Molien series for complete weight enumerators of Euclidean self-dual codes over the Galois ring GR(4,2).at n=14A099720
- Numbers k such that f(k), f(k+1) and f(k+2) are all primes, where f(k) = 8*k^2 + 4*k + 1.at n=41A103777
- Expansion of (chi(-q^3)^8 + 16*q^2/ chi(-q^3)^8)^(1/8) in powers of q where chi() is a Ramanujan theta function.at n=10A106204
- a(n) = (n^7 - n)/6.at n=5A108495
- Number of closed walks of length n on the complete graph on 6 nodes from a given node.at n=7A109500