12111
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
- 8
- Divisor Sum
- 17664
- Proper Divisor Sum (Aliquot Sum)
- 5553
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7320
- Möbius Function
- -1
- Radical
- 12111
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 94
- 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
- Numbers that contain only 1's and 2's. Nonempty binary strings of length n in lexicographic order.at n=38A007931
- a(n)-th prime is sum of first k primes for some k.at n=27A020641
- Number of lattice paths from (0,0) to (n,n) with steps (0,1), (1,0) and, when on the diagonal, (1,1).at n=7A026671
- a(n) = T(n, floor(n/2)), T given by A026670.at n=14A026676
- a(n) = T(n, floor(n/2)), T given by A026736.at n=15A026742
- a(n) = greatest number in row n of array T given by A026736.at n=15A027214
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 20.at n=10A031698
- Numbers having four 1's in base 10.at n=29A043496
- a(n) = concatenation of n^2 and n.at n=10A055436
- a(n) = 100*n^2 + n.at n=10A055438
- Number of powerful numbers not exceeding 2^n.at n=25A062762
- The zero-free, right-to-left factorial walk encoding for each rooted plane tree encoded by A014486. Sequence A071155 shown with factorial expansion (A007623).at n=25A071157
- Factorial expansion of A071156.at n=27A071158
- Integers whose decimal expansion start with 1, do not contain zeros and each successive digit to the right is at most one greater than the previous digit.at n=36A071159
- Leftmost 1 is converted to a 2, which then propagates one step at a time until it is rightmost; then it changes to a pair of 1's and the process repeats.at n=17A071762
- Variant of the factorial base representation of n.at n=39A072001
- Numbers in base -3.at n=34A073785
- Numbers n such that sum of squares of even digits of n equals sum of squares of odd digits of n.at n=10A076164
- Left-to-right binary enumeration.at n=32A081242
- a(1) = 1, then the smallest number not included earlier and not a string of 1's such that the concatenation a(n), a(n+1) is a palindrome.at n=12A083122