12549
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
- 8
- Divisor Sum
- 17280
- Proper Divisor Sum (Aliquot Sum)
- 4731
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8096
- Möbius Function
- -1
- Radical
- 12549
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 37
- 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
- Number of partitions of n with equal number of even and odd parts.at n=50A045931
- Sum_{i=0..n} (C(n,i) mod 2)*Fibonacci(2i+1) = FL(n+1)Product(L(2^i)^bit(n,i),i=0..).at n=10A050611
- a(n+1) = a(n)/2 if 2|a(n), a(n)/3 if 3|a(n), a(n)/5 if 5|a(n), a(n)/7 if 7|a(n), a(n)/11 if 11|a(n), a(n)/13 if 13|a(n), otherwise 17*a(n)+1.at n=16A057534
- Numbers k such that sigma(k) = phi(k*bigomega(k)+1).at n=42A067876
- Numbers k such that sigma(k) = phi(k*omega(k)+1).at n=44A067879
- Average of terms of n-th row of A077321.at n=36A077325
- Short leg of primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.at n=26A089547
- n - (sum of prime factors of n^2+1) is a positive square.at n=36A216896
- Number of partitions p of n such that the multiplicity of the mean of p is a part of p.at n=55A240491
- Numbers obtained by concatenating the squares of the digits of prime(n).at n=36A244557
- Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 4 6 or 7.at n=7A252551
- T(n,k) = Number of (n+2) X (k+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 1 2 4 6 or 7.at n=35A252558
- Number of length n+4 0..3 arrays with at most one downstep in every 4 consecutive neighbor pairs.at n=3A258726
- T(n,k)=Number of length n+k 0..3 arrays with at most one downstep in every k consecutive neighbor pairs.at n=24A258730
- Number of length n+4 0..3 arrays with at most one downstep in every n consecutive neighbor pairs.at n=3A258734
- T(n,k)=Number of nXk arrays containing k copies of 0..n-1 with no element 1 greater than its north, southwest or northwest neighbor modulo n and the upper left element equal to 0.at n=31A266878
- Number of 4Xn arrays containing n copies of 0..4-1 with no element 1 greater than its north, southwest or northwest neighbor modulo 4 and the upper left element equal to 0.at n=4A266880
- Number of non-isomorphic multiset partitions of weight n in which (1) all parts have the same size and (2) each vertex appears the same number of times.at n=24A319056
- Numbers that are the sum of nine fourth powers in nine or more ways.at n=18A345593
- Numbers that are the sum of nine fourth powers in exactly nine ways.at n=17A345851