12020
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 5
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 25284
- Proper Divisor Sum (Aliquot Sum)
- 13264
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4800
- Möbius Function
- 0
- Radical
- 6010
- Omega Function (Ω)
- 4
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 143
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Number of positive integers <= 2^n of form 2*x^2 + 3*y^2.at n=16A000075
- Number of partially achiral rooted trees.at n=15A003240
- 4-dimensional analog of centered polygonal numbers.at n=14A006322
- a(n) = n*(15*n + 1)/2.at n=40A022273
- In the list of divisors of n (in base 3), each digit 0-2 appears equally often.at n=4A045811
- Each permutation in the list A060118 converted to Site Swap notation, with digits reversed and inverted. "Zero throws" (fixed elements) indicated with 0's.at n=36A060499
- Multiples of 5 with digit sum 5.at n=31A069540
- Totally balanced decimal numbers: if we assign the weight w(d) = d-1 to each digit d (i.e., w(0) = -1, w(1) = 0, ..., w(9) = 8) and then read the digits of the term from left to right, the partial sum of the weights is never negative and the total weighted sum is zero.at n=28A071154
- Łukasiewicz words that are also valid asynchronic siteswap juggling patterns.at n=26A071160
- Integers whose decimal expansion satisfies the condition that if we read each term from the left to right (the most significant to the least significant digit) then each nonzero digit gives a distance to the next nonzero digit to right (with a cyclic wrap-over from the least-significant to the most significant nonzero digit).at n=21A071161
- Numbers in base -3.at n=21A073785
- "Lazy binary" representation of n. Also called redundant binary representation of n.at n=36A089591
- Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+601)^2 = y^2.at n=6A111258
- Generalized Pascal's triangle made using Mod[(Prime[n] - 1)/2, 4] == 2 primorial-like Stirling polynomials.at n=51A119724
- G.f. satisfies A(x) = 1 + x*(1 + x*A(x)^5)^4.at n=6A137964
- a(n) = 1000*n + 20.at n=11A157510
- Nonprimes such that it takes exactly 4 iterations of reverse-and-add digits to generate a prime.at n=22A245209
- Expansion of f(-x^2, -x^10) / f(-x, -x) in powers of x where f(, ) is Ramanujan's general theta function.at n=25A262984
- Number of n X 4 binary arrays with rows and columns lexicographically nondecreasing and row and column sums nonincreasing.at n=30A266543
- Number of compositions (ordered partitions) of n into distinct parts, the least being 4.at n=44A339165