12844
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
- 3
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 25620
- Proper Divisor Sum (Aliquot Sum)
- 12776
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5616
- Möbius Function
- 0
- Radical
- 494
- Omega Function (Ω)
- 5
- 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
- 125
- 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
- For each prime p take the sum of nonprimes < p.at n=40A045717
- A simple context-free grammar: difference between A049140 and its convolution square.at n=11A052710
- Numbers k such that k and its reversal are both multiples of 19.at n=36A062907
- Non-palindromic number and its reversal are both multiples of 19.at n=25A062916
- a(1)=1, a(n)=2a(n-1)+1 if a(n-1) is prime, a(n)=a(n-1)+1 otherwise.at n=46A083005
- Fourth column of (1,5)-Pascal triangle A096940.at n=37A096941
- A Chebyshev transform of A099456 associated to the knot 9_44.at n=13A099457
- a(n) = floor((x^n - (1-x)^n) / (2x-1) +.5) where x = (sqrt(6)+1)/2 (and hence 2x-1 = sqrt(6)).at n=18A136424
- Totally multiplicative sequence with a(p) = 7p-1 for prime p.at n=43A166656
- a(n) = n^3/6 + 3*n^2/4 + 7*n/3 + 7/8 + (-1)^n/8.at n=41A173154
- spt(n) - p(n): total number of smallest parts in all partitions of n minus the number of partitions of n.at n=27A215513
- Number of subsets of {1,2,...,n-9} without differences equal to 3, 6 or 9.at n=35A224814
- a(n) = Sum_{i=0..n} digsum_5(i)^4, where digsum_5(i) = A053824(i).at n=23A231671
- Numbers k whose decimal expansion can be split into at least two parts whose binary equivalents can be concatenated (in the same order) to form the binary expansion of the original number k.at n=24A237041
- a(n) = 19*n^2.at n=26A244631
- Erroneous version of A001002.at n=8A259690
- Composites whose prime factorization in base 3 is an anagram of the number in base 3.at n=29A260047
- a(n) = 4*n*(21*n - 26).at n=13A263229
- Numbers equal to the sum of their aliquot parts, each of them increased by 4.at n=7A304277
- Smallest k > 0 with gcd(k, rev(k)) = n, where rev(k) is digit reversal of k and with sum of digits of k = n, or 0 if no such k exists.at n=18A333666