12057
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16080
- Proper Divisor Sum (Aliquot Sum)
- 4023
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8036
- Möbius Function
- 1
- Radical
- 12057
- 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
- 187
- 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
- Numbers k such that k^2 and k^3 have the same set of digits.at n=16A029797
- Number of partitions of 2n in which odd parts and multiples of 3 and 5 occur with even multiplicities. There is no restriction on the other even parts.at n=25A102346
- Next term is the sum of previous term and the square of the sum of its decimal digits, with a(0) = 10.at n=41A112787
- a(n) = 104*n + 9977.at n=20A126978
- Lower triangular array called S2hat(-1) related to partition number array A144269.at n=38A144270
- Third column (m=3) of triangle S2hat(-1) = A144270.at n=6A144273
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (-1, 1, -1), (0, -1, 1), (1, 0, 0)}.at n=11A148033
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, -1, 1), (-1, 0, 1), (0, 0, -1), (1, 1, 1)}.at n=8A149585
- Similar to A072921 but starting with 3.at n=42A152232
- Number of nondecreasing arrangements of n+2 numbers in 0..3 with each number being the sum mod 4 of two others.at n=37A183906
- Numbers n such that n and n+1 have same sum of anti-divisors.at n=9A192282
- Numbers n such that n^2 + 1 is divisible by a 4th power.at n=39A218563
- Expansion of Product_{k>=1} (1 + x^(k^2))^(k^2).at n=49A291649
- Consider binary words that begin with 1 such that the subword 00, whenever it appears, is followed by 111. Then a(n) counts such words at length n (including those where the string 111 is yet being completed - see Example).at n=17A340217
- a(n) = Sum_{k=1..n} k * floor(n/k)^3.at n=19A350108
- G.f. A(x) satisfies: [x^n] A(x)^(n+1) = [x^n] (1 + x*A(x)^(n+3))^(n+1) for n >= 0.at n=5A360235
- G.f. satisfies A(x) = 1 + x*A(x)^2 + x^2*A(x)^6.at n=7A364473
- G.f. satisfies A(x) = 1 + x^4*A(x)*(1 + x*A(x)).at n=37A365727
- Numbers k such that k, k + 1, k + 2, and k + 4 are all semiprimes.at n=38A368670
- a(n) = n^5/5 + n^3/3 + 7*n/15.at n=9A385894