12217
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12880
- Proper Divisor Sum (Aliquot Sum)
- 663
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11556
- Möbius Function
- 1
- Radical
- 12217
- 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
- 37
- 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
- Expansion of Product_{m>=1} (1 + m*q^m)^19.at n=4A022647
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 64 ones.at n=25A031832
- If p(x) is the x-th prime, then the n-th set of 4 consecutive sexy prime pairs starts at p(a(n)).at n=18A095963
- If p(x) is the x-th prime, then the n-th set of 5 consecutive sexy prime pairs starts at p(a(n)).at n=4A095964
- a(1) = 932; for n > 1, a(n) = a(n-1) + 1 + sum of distinct prime factors of a(n-1) that are < a(n-1).at n=33A105213
- Numbers k such that the concatenation of k with k-8 gives a square.at n=3A115435
- Numbers k such that k concatenated with k-9 gives the product of two numbers which differ by 2.at n=3A116095
- E.g.f. exp(x)*(Bessel_I(0,2*sqrt(2)x) + Bessel_I(1,2*sqrt(2)x)/sqrt(2)).at n=8A119975
- Number of base 13 circular n-digit numbers with adjacent digits differing by 1 or less.at n=8A124706
- Number T(n,k) of entries in the k-th cycles of all permutations of {1,2,..,n}; each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements.at n=31A185105
- Number of partitions of n such that the number of parts and the greatest part are not coprime.at n=38A200792
- Number of partitions p of n not containing ceiling((min(p) + max(p))/2) as a part.at n=35A238485
- Index sequence for limit-reversing A000002; see Comments.at n=39A245937
- Start with a single hexagon; at n-th generation add a hexagon at each expandable vertex; a(n) is the sum of all label values at n-th generation. (See comment for construction rules.)at n=10A247620
- Number of n X n 0..2 arrays with no element equal to any value at offset (0,-1), (-1,-1) or (-2,0) and new values introduced in order 0..2.at n=5A274889
- Number of nX6 0..2 arrays with no element equal to any value at offset (0,-1) (-1,-1) or (-2,0) and new values introduced in order 0..2.at n=5A274893
- Number of 6Xn 0..2 arrays with no element equal to any value at offset (0,-1) (-1,-1) or (-2,0) and new values introduced in order 0..2.at n=5A274898
- Number of entries in the fourth cycles of all permutations of [n].at n=4A285232
- Number of entries in the n-th cycles of all permutations of [2n].at n=3A285239
- Triangle read by rows: T(m,n) (1 <= n < m) is the number of moves of an (m,n)-leaper (a generalization of a chess knight) until it can no longer move, starting on a board with squares spirally numbered from 1. Each move is to the lowest-numbered unvisited square. T(m,n) = -1 if the path never terminates.at n=16A323749