12657
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16880
- Proper Divisor Sum (Aliquot Sum)
- 4223
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8436
- Möbius Function
- 1
- Radical
- 12657
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 81
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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 k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 74.at n=38A031572
- Triangle read by rows: matrix cube of the Stirling-1 triangle A008275.at n=16A039815
- 53 'Reverse and Add' steps are needed to reach a palindrome.at n=2A065320
- a(n) = 16*n^2 + 4*n + 1.at n=28A082041
- Number of n X n permutation matrices in which the sums of the entries of each NorthEast-SouthWest diagonal are 0 or 1.at n=9A099152
- p^2-p+1 central polygonal numbers with prime indices A002061(prime(n)).at n=29A119959
- Triangle read by rows: T(n,k) is the number of permutations p of {1,2,...,n} such that the set {p(i)-i, i=1,2,...,n} has exactly k elements (1<=k<=n).at n=44A125182
- a(n) = ceiling(n^4/4).at n=15A131478
- Number of (v,w,x,y,z) with all terms in {0,1,...,n} and v=average(w,x,y,z).at n=14A212257
- Number of (w,x,y,z) with all terms in {1,...,n} and w >= |x-y| + |y-z|.at n=13A212675
- Numbers n such that Q(sqrt(n)) has class number 9.at n=20A218041
- Fundamental discriminants of real quadratic number fields with class number 9.at n=12A218159
- Number of n X 3 0..1 arrays with rows, antidiagonals and columns unimodal.at n=6A223632
- Number of nX7 0..1 arrays with rows, antidiagonals and columns unimodal.at n=2A223636
- T(n,k)=Number of nXk 0..1 arrays with rows, antidiagonals and columns unimodal.at n=38A223637
- T(n,k)=Number of nXk 0..1 arrays with rows, antidiagonals and columns unimodal.at n=42A223637
- Array read by antidiagonals. Rows are the numerators of consecutive harmonic transforms starting with a first row 1, 1, 1, ....at n=33A229556
- Number of length 2+3 0..n arrays with some disjoint pairs in every consecutive four terms having the same sum.at n=13A247534
- The pi-based arithmetic derivative of the n-th Fibonacci number.at n=21A259416
- Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 470", based on the 5-celled von Neumann neighborhood.at n=14A282422