13285
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 15948
- Proper Divisor Sum (Aliquot Sum)
- 2663
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10624
- Möbius Function
- 1
- Radical
- 13285
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 107
- 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
- no
- Odd
- yes
Appears in sequences
- Chance of getting no pair, a pair, 2 pair, 3 of a kind, other straight, other flush, full house, 4 of a kind, other straight flush, a royal flush, or 5 of a kind in poker when joker is wild is 1 in a(n) (rounded to nearest integer).at n=8A014358
- Numbers k such that the continued fraction for sqrt(k) has period 65.at n=13A020404
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/(2*n)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=42A024845
- Numbers k that divide the (right) concatenation of all numbers <= k written in base 17 (most significant digit on left).at n=11A029462
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 21.at n=18A051986
- a(n) = (2*n-1)^2 + (2*n)^2.at n=40A060820
- a(n) = (prime(n)^2 + 1)/2.at n=36A066885
- a(n) = 8*n^2 - 4*n + 1.at n=41A080856
- Downward vertical of triangular spiral in A051682.at n=27A081272
- Least k such that prime(n)^2 divides binomial(2k,k).at n=37A110494
- Numbers k such that the k-th triangular number contains only digits {2,5,8}.at n=8A119169
- Numbers n such that primorial(n)/2 - 64 is prime.at n=28A139448
- The number of reachable states in a simple two-player counting game, in which each player starts with the pair (1,1) and one move is to add one of the opponent's numbers to one of your own numbers, but no number can grow above a pre-defined maximum n. The game continues until one of the players has no legal moves left. The winner is the one having the higher sum of his numbers.at n=17A161531
- Number of non-intersecting unit cubes regularly packed into the tetrahedron of edge length n.at n=49A219965
- Numbers k^2 + (k+1)^2 that can be expressed as a sum of two squares in exactly one other way.at n=37A239527
- Number of length n 1..(5+1) arrays with every leading partial sum divisible by 2, 3, 5, 7 or 11.at n=5A254944
- T(n,k) is the number of length n 1..(k+1) arrays with every leading partial sum divisible by 2, 3, 5, 7 or 11.at n=50A254947
- Number of length 6 1..(n+1) arrays with every leading partial sum divisible by 2, 3, 5, 7 or 11.at n=4A254953
- Odd numbers m that are neither of the form p + 2^k nor of the form p - 2^k with 2^k < m, k >= 1, and p prime.at n=14A255967
- Subsequence of centered square numbers obtained by adding four triangles from A276914 and a central element, a(n) = 4*A276914(n) + 1.at n=41A276916