12926
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 20304
- Proper Divisor Sum (Aliquot Sum)
- 7378
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6160
- Möbius Function
- -1
- Radical
- 12926
- 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
- 169
- 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
- yes
- Odd
- no
Appears in sequences
- 4-dimensional analog of centered polygonal numbers. Also number of regions created by sides and diagonals of a convex n-gon in general position.at n=25A006522
- Number of regions in regular n-gon with all diagonals drawn.at n=24A007678
- The least k such that A063994(k) = Product_{primes p dividing k} gcd(p-1, k-1) = n, or 0 if there's no such k.at n=54A064234
- Diagonal in array of n-gonal numbers A081422.at n=22A081438
- Indices of primes in sequence defined by A(0) = 71, A(n) = 10*A(n-1) + 21 for n > 0.at n=22A101137
- Number of chambers in root systems of type D_n.at n=3A119670
- Product of the first n 4-almost primes, divided by product of the first n primes, rounded down.at n=4A122093
- Second differences of sequence A160644.at n=39A160648
- Successive records in maximal positive distance d = x^3 - y^2.at n=46A198831
- Numbers k with property that for every base b >= 2, there is a number m such that m+s(m) = k, where s(m) = sum of digits in the base-b expansion of m.at n=41A230624
- Number of partitions p of n such that mean(p) <= multiplicity(min(p)).at n=38A240204
- a(n) = n * Sum_{k prime<=n} k.at n=45A301707
- Indices of primes followed by a gap (distance to next larger prime) of 44.at n=9A320720
- MM-numbers of capturing, non-nesting multiset partitions (with empty parts allowed).at n=17A326260
- Number of (binary) max-heaps on n elements from the set {0,1} containing exactly four 0's.at n=45A326505
- a(n) = A007678(2*n+1).at n=12A341735
- a(n) is the least number k such that the sum of n^2 consecutive primes starting at prime(k) is a square.at n=46A357813
- Number of integer compositions of n whose leaders of weakly increasing runs are strictly increasing.at n=23A374634