12685
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 15840
- Proper Divisor Sum (Aliquot Sum)
- 3155
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9744
- Möbius Function
- -1
- Radical
- 12685
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 81
- 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
- no
- Odd
- yes
Appears in sequences
- Triangle of numbers of permutations eliminating just k cards out of n in game of Mousetrap.at n=50A028305
- [ exp(12/13)*n! ].at n=6A030922
- Numerators of continued fraction convergents to sqrt(497).at n=5A041948
- a(n) = (1/3!)*(n^3 + 24*n^2 + 107*n + 90), compare A059604.at n=35A059605
- Numbers k such that prime(k) + prime(k+1) is a square.at n=33A064397
- Numbers k such that prime(k) + prime(k+1) is a perfect power.at n=39A132746
- Ulam's spiral (SSW spoke).at n=28A143838
- Numbers k such that R_k + 60 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=14A256760
- Number of length 4 1..(n+1) arrays with every leading partial sum divisible by 2 or 3.at n=14A257066
- The x member of the positive proper fundamental solution (x = x2(n), y = y2(n)) of the second class for the Pell equation x^2 - D(n)*y^2 = +8 for odd D(n) = A263012(n).at n=21A264351
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 315", based on the 5-celled von Neumann neighborhood.at n=26A271248
- Number of not unique partition coefficients of n.at n=36A309897
- Composite numbers k coprime to 13 such that k divides A006190(k-Kronecker(13,k)).at n=11A327653
- Number of compositions of n whose non-adjacent parts are strictly decreasing.at n=36A333193
- Odd composite integers m such that A006497(2*m-J(m,13)) == 3*J(m,13) (mod m), where J(m,13) is the Jacobi symbol.at n=35A339518
- Number of semi-sums of integer partitions of n.at n=25A366738