12827
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13056
- 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
- 12600
- Möbius Function
- 1
- Radical
- 12827
- 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
- 76
- 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
- a(n) = Sum_{i=0..n} T(i,n-i), array T as in A048149.at n=28A049712
- Indices of primes in the sequence defined by A(0) = 29, A(n) = 10*A(n-1) - 21 for n > 0.at n=15A101965
- Expansion of 2/(sqrt(1-2*x-3*x^2)*(1+x+sqrt(1-2*x-3*x^2))).at n=10A113682
- a(n) = (4*n^3 - 9*n^2 + 11*n + 3)/3.at n=22A161707
- Symmetric matrix based on A007598(n+1), by antidiagonals.at n=48A203003
- Squarefree numbers (A005117) with prime factors in a prime(k) + k progression.at n=8A232169
- Squarefree numbers (A005117) of form prime(k)*q where q = primes of the form prime(k) + k.at n=7A232170
- Number of factorizations of m^2 into 2 factors, where m is a product of exactly n distinct primes and each factor is a product of n primes (counted with multiplicity).at n=11A257520
- Semiprimes whose prime factors are of equal binary length and which differ from each other in exactly three bit positions.at n=33A261075
- a(n) = A277715(n) / 3.at n=54A277716
- a(n) = -n^3 + 70*n^2 - 939*n + 2393.at n=37A279538
- Expansion of Product_{1 <= i_1 <= i_2 <= i_3 <= i_4} (1 + x^(i_1*i_2*i_3*i_4)).at n=38A321567
- a(1) = 1; for n > 1, a(n) is the least odd number k such that A325567(k) = 2*n-1, or 0 if no such number exists.at n=50A379128