12942
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 28080
- Proper Divisor Sum (Aliquot Sum)
- 15138
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4308
- Möbius Function
- 0
- Radical
- 4314
- Omega Function (Ω)
- 4
- 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
- 169
- 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 one-sided hexagonal polyominoes with n cells.at n=8A006535
- Denominators of continued fraction convergents to sqrt(165).at n=8A041305
- McKay-Thompson series of class 38a for Monster.at n=45A058658
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=5A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=25A103950
- a(n) is the number of distinct n-th powers of functions {1, 2, 3, 4, 5, 6} -> {1, 2, 3, 4, 5, 6}.at n=35A103950
- Number of different 5th-power (quintic) mappings of a finite set of n elements into itself.at n=6A163861
- a(n)=floor(3*n^2*(2+sqrt(3))).at n=33A172526
- Number of 2 X 2 matrices with all elements in {0,1,...,n} and determinant in {-1,0,1}.at n=35A209993
- Numbers n such that n^2 is a sum of 2 and also of 4 consecutive primes.at n=15A252066
- Number of nX5 0..1 arrays with every element equal to 0, 1, 3, 4 or 7 king-move adjacent elements, with upper left element zero.at n=7A298498
- G.f.: 1 + Sum_{n>=1} a(n)*x^n/(1 - x^n) = Product_{n>=1} (1 + x^n)/(1 - x^n).at n=21A300274
- Expansion of Product_{k>=1} (1 - Sum_{j>=1} j * x^(k*j)).at n=38A329157
- a(n) = Sum_{i=1..n} sigma(i)*sigma(i+1), where sigma(n) = A000203(n) is the sum of the divisors of n.at n=23A330322
- Irregular table read by rows: T(n,k) is the number of permutations in S_n that have exactly k occurrences of the pattern 2413. 0 <= k <= A342854(n).at n=50A342860
- Smallest integer that is the sum of a prime and the square of a prime in n or more ways.at n=22A381333
- Smallest integer that is the sum of a prime and the square of a prime in exactly n ways.at n=22A381334
- Number of maximum sized subsets of {1..n} such that every pair of distinct elements has a different sum.at n=34A382398
- a(n) = Sum_{k=0..n} 3^k * 2^(n-k) * binomial(3*n+1,k) * binomial(3*n-k,n-k).at n=3A386830