12495
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
- 24
- Divisor Sum
- 24624
- Proper Divisor Sum (Aliquot Sum)
- 12129
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5376
- Möbius Function
- 0
- Radical
- 1785
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 187
- 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
- Numbers k such that 9*2^k - 1 is prime.at n=28A002236
- a(0) = 1, a(n) = 13*n^2 + 2 for n>0.at n=31A010004
- Future of the smallest-perizeroin komet in Kimberling's expulsion array (A035486).at n=29A038807
- Triangle read by rows: matrix cube of the Stirling2 triangle A008277.at n=24A039811
- Numbers whose base-4 representation contains exactly three 0's and four 3's.at n=1A045080
- Triangle read by rows, the Bell transform of (n+2)!/2 without column 0.at n=24A046089
- Truncated triangular pyramid numbers: a(n) = Sum_{k=9..n} (k*(k+1)/2 - 45).at n=34A051943
- Number of symmetric types of (3,2n)-hypergraphs under action of complementing group C(3,2).at n=33A055780
- a(n) = (1/6)*(2*n - 3)*(n + 2)*(n + 1).at n=35A058373
- Numbers k such that reverse(gpf(k)) = gpf(k+1), where gpf(n) = A006530(n); a(1)=1.at n=22A071844
- Number of lesser twin primes (A001359) in range ]2^n, 2^(n+1)].at n=20A095017
- Numbers k for which nontrivial positive magic squares of exactly 9 different orders with magic sum k exist. For a definition of nontrivial positive magic squares, see A125005.at n=19A125016
- Unsigned fifth column (k=4) of triangle A136656 divided by 16.at n=3A136661
- a(n) = (-1)^n*n*(n+1)*(2*n-5)/6.at n=33A167386
- a(n) = 7*A000330(n).at n=17A169607
- [s(k)-s(j)]/6, where the pairs (k,j) are given by A205857 and A205858, and s(k) denotes the (k+1)-st Fibonacci number.at n=40A205860
- Number of nX3 arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.at n=3A221505
- T(n,k)=Number of nXk arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.at n=18A221507
- Triangle read by rows: T(n,k) is the coefficient in the transformation Sum_{k=0..n} (k+1)*x^k = Sum_{k=0..n} T(n,k)*(x-k)^k.at n=42A247237
- Number of length 3+1 0..n arrays with the sum of the squares of adjacent differences multiplied by some arrangement of +-1 equal to zero.at n=37A250278