12249
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 17706
- Proper Divisor Sum (Aliquot Sum)
- 5457
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8160
- Möbius Function
- 0
- Radical
- 4083
- Omega Function (Ω)
- 3
- 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
- 112
- 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
- no
- Odd
- yes
Appears in sequences
- Josephus problem: numbers m such that, when m people are arranged on a circle and numbered 1 through m, the final survivor when we remove every 4th person is one of the first three people.at n=27A005427
- a(n) = Sum_{i=0..floor(n/2)} T(2i,n-2i), array T as in A048149.at n=35A049714
- Variant of Lucas numbers: a(n) = a(n-1) + 4*a(n-2) starting with a(0)=2 and a(1)=1.at n=10A072265
- a(1) = 1 and a(n) = ceiling((Sum_{k=1..n-1} a(k))/3) for n >= 2.at n=35A072493
- Second binomial transform of expansion of cosh(sinh(x)).at n=8A081444
- Duplicate of A072265.at n=10A085488
- Number of prime pairs below 10^n having a difference of 26.at n=6A093748
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, 1, -1), (1, -1, -1), (1, 0, 1)}.at n=9A148774
- a(n) = 10*n^2 - 1.at n=34A158447
- The smallest constant of an n X n associative magic square composed of distinct primes.at n=6A188537
- Coefficient of x in the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=15A192389
- Number of (n+4) X 7 0..1 matrices with each 5 X 5 subblock idempotent.at n=12A224685
- a(n) = 324*n^2 - 564*n + 321 (n>=1).at n=6A304617
- Odd numbers for which sigma(k) is congruent to 2 modulo 4 and the 3-adic valuation of k is one larger than the 3-adic valuation of sigma(k).at n=43A351534
- The fixed points of A355702.at n=29A356017
- Number of integer partitions of n having at most one permutation with all equal run-lengths.at n=41A383092
- The numbers of people such that, in the variant of the Josephus problem in which three people are skipped and then one is eliminated, the first person is the last to be eliminated.at n=10A385327