12707
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12936
- Proper Divisor Sum (Aliquot Sum)
- 229
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12480
- Möbius Function
- 1
- Radical
- 12707
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 55
- 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
- Composite numbers x such that sigma(x+120) = sigma(x)+120.at n=25A054985
- Numbers n such that sigma(n+2) - sigma(n) = prime(n+2) - prime(n).at n=11A067058
- Numbers k such that sigma(phi(sigma(k))) = phi(sigma(phi(k))).at n=12A067160
- Numerator of b(n) where b(n+1) = Sum_{k=0..n} b'((n^2-k^2)/n), b(0) = b(1) = 1, and b'(x) = b(x) if x is an integer and is linearly interpolated otherwise.at n=7A071300
- Number of partitions of 2n in which all odd parts occur with multiplicity 2. There is no restriction on the even parts.at n=26A101277
- Iccanobirt prime indices (12 of 15): Indices of prime numbers in A102122.at n=21A102142
- Composite solutions of the form 4k+3 of the equation (*): sigma(phi(sigma(x)))=phi(sigma(phi(x))).at n=2A112017
- a(1) = a(2) = 1. a(n) = a(n-1) + (largest nonprime {1 or composite} among the first n-2 terms of the sequence).at n=23A120760
- Triangle read by rows: T(0,0)=1; T(n,k) is the coefficient of x^k in the polynomial (-1)^n*p(n,x), where p(n,x) is the characteristic polynomial of the n X n tridiagonal matrix with 3's on the main diagonal and -1's on the super- and subdiagonal (n >= 1; 0 <= k <= n).at n=38A123965
- Duplicate of A123965.at n=38A124025
- A convolution triangle of numbers based on A001906 (even-indexed Fibonacci numbers).at n=38A125662
- a(n) = n*(n-th prime) + (n+1)*((n+1)-th prime).at n=37A152117
- Triangle, read by rows, given by [0,1/3,-1/3,0,0,0,0,0,0,0,...] DELTA [3,-1/3,1/3,0,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938.at n=63A172249
- Triangle read by rows: T(n,k) is the number of ternary words (i.e., finite sequences of 0's, 1's and 2's) of length n having k occurrences of 01's (0 <= k <= floor(n/2)).at n=32A181371
- Triangle of coefficients of Chebyshev's S(n,x-3) polynomials (exponents of x in increasing order).at n=38A207815
- Expansion of 1/(1 - 3*x + x^2)^3.at n=6A246178
- Numbers that form a Pythagorean 5-tuple with their first three arithmetic derivatives.at n=5A249105
- Number of length n+4 0..6 arrays with every five consecutive terms having four times some element equal to the sum of the remaining four.at n=8A249654
- Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 0 and no antidiagonal sum 0 and no row sum 0 or 1 and no column sum 0 or 1.at n=6A256803
- Number of (n+2)X(7+2) 0..1 arrays with no 3x3 subblock diagonal sum 0 and no antidiagonal sum 0 and no row sum 0 or 1 and no column sum 0 or 1.at n=0A256809