10905
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 17472
- Proper Divisor Sum (Aliquot Sum)
- 6567
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5808
- Möbius Function
- -1
- Radical
- 10905
- Omega Function (Ω)
- 3
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 68
- 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
- no
- Odd
- yes
Appears in sequences
- Wedderburn-Etherington numbers: unlabeled binary rooted trees (every node has outdegree 0 or 2) with n endpoints (and 2n-1 nodes in all).at n=16A001190
- Multiplicity of highest weight (or singular) vectors associated with character chi_111 of Monster module.at n=37A034499
- Number of partitions of n into parts not of the form 25k, 25k+5 or 25k-5. Also number of partitions with at most 4 parts of size 1 and differences between parts at distance 11 are greater than 1.at n=35A036004
- Number of n-node rooted unlabeled trees with outdegree <= 2 and exactly 1 edge at the root.at n=16A036656
- Numerators of continued fraction convergents to sqrt(242).at n=8A041452
- Numbers of the form p*q*r where p,q,r are distinct odd palindromic primes (odd terms from A002385).at n=40A046405
- a(n)=det(M_n) where M_n is the n X n matrix m(i,j)=1 if sigma(i+j) is even, 0 otherwise.at n=27A096734
- Number of totally ramified extensions over Q_3 with degree n in the algebraic closure of Q_3.at n=14A100980
- Numbers that appear exactly five times in A101402. (Also indices of fives in A101403.).at n=7A129117
- a(n) = ((5 + 2*sqrt(2))*(1 + sqrt(2))^n + (5 - 2*sqrt(2))*(1 - sqrt(2))^n)/2.at n=9A163607
- Numbers n such that (ceiling(sqrt(n*n/2)))^2 - n*n/2 = 17/2.at n=8A175033
- Number of 2 X 2 matrices having all elements in {0,1,...,n} and determinant in the open interval (-n,n).at n=13A211032
- a(0)=1, a(n) = a(n-1) + a(2*n AND n), where AND is the bitwise AND operator.at n=38A215488
- 27-gonal numbers: a(n) = n*(25*n-23)/2.at n=30A255186
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 654", based on the 5-celled von Neumann neighborhood.at n=32A273332
- Numbers n such that the Collatz iterations for n and n + 1 have the same length (A078417) but do not meet a certain condition. (See comments.)at n=11A274410
- Numbers k such that (14*10^k - 143)/3 is prime.at n=18A279050
- Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 361", based on the 5-celled von Neumann neighborhood.at n=28A281412
- The concatenation pkp is the number obtained by placing prime p either side of R_k, the k-th repunit (1, k times); a(n) is the smallest k such that pkp is prime, where p=prime(n), or -1 if no such k exists.at n=3A307873
- Odd composite integers m such that A052918(m-J(m,29)) == 0 (mod m) and gcd(m,29)=1, where J(m,29) is the Jacobi symbol.at n=17A340095