12531
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16712
- Proper Divisor Sum (Aliquot Sum)
- 4181
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8352
- Möbius Function
- 1
- Radical
- 12531
- 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
- 86
- 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
- G.f.: 1/((1-x)*(1-x^2)*(1-x^3)^2*(1-x^4)*(1-x^5)).at n=47A003402
- Expansion of Product(1+q^m)^(m(m-1)/2); m=1..inf.at n=16A027999
- Numbers in which all pairs of consecutive base-8 digits differ by 3.at n=51A033079
- Number of partitions of n into parts not of the form 19k, 19k+9 or 19k-9. Also number of partitions with at most 8 parts of size 1 and differences between parts at distance 8 are greater than 1.at n=36A035978
- Numbers whose base-4 representation contains exactly three 0's and four 3's.at n=2A045080
- a(n) is the number of integers x that can be written x = (2^c(1) - 2^c(2) - 3*2^c(3) - 3^2*2^c(4) - ... - 3^(m-2)*2^c(m) - 3^(m-1)) / 3^m for integers c(1), c(2), ..., c(m) such that n = c(1) > c(2) > ... > c(m) > 0 and c(1) - c(2) != 2 if m >= 2.at n=38A131450
- Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 0110-1111-0100 pattern in any orientation.at n=10A146587
- a(0)=2, a(n) = n^2+a(n-1).at n=33A153056
- a(n) = A056520(n)+1 for n>0, a(0)=1.at n=33A179904
- Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,3,0,1,1 for x=0,1,2,3,4.at n=6A197891
- Number of nX7 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,3,0,1,1 for x=0,1,2,3,4.at n=2A197895
- T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,3,0,1,1 for x=0,1,2,3,4.at n=38A197896
- T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,3,0,1,1 for x=0,1,2,3,4.at n=42A197896
- a(n) = A277715(n) / 3.at n=52A277716
- Consecutive states of the linear congruential pseudo-random number generator (2041*s + 25673) mod 121500 when started at s=1.at n=10A385362
- Irregular triangle read by rows: T(n,k) is the number of polyominoes of size k, i.e., connected subsets of k square cells (or vertices), of the n X n flat torus, up to cyclic shifts and reflections of rows and columns, as well as interchange of rows and columns; 1 <= k <= n^2.at n=43A385385