2220
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 6
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 6384
- Proper Divisor Sum (Aliquot Sum)
- 4164
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 576
- Möbius Function
- 0
- Radical
- 1110
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- 32
- 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
- An approximation to population of x^2 + y^2 <= 2^n.at n=13A000692
- Number of n-bead necklaces with beads of 2 colors and primitive period n, when turning over is allowed.at n=16A001371
- Numbers k such that the k-th tetrahedral number is the sum of 2 tetrahedral numbers.at n=48A002311
- Coordination sequence T1 for Zeolite Code ATS.at n=34A008038
- Coordination sequence T1 for Zeolite Code LTL.at n=35A008138
- Coordination sequence T4 for Zeolite Code ZON.at n=33A009922
- a(n) = floor(n*(n-1)*(n-2)/21).at n=37A011903
- a(n+2) = (2n+3)*a(n+1) + (n+1)^2*a(n), a(0) = 1, a(1) = 1.at n=5A012244
- Number of lines through exactly 9 points of an n X n grid of points.at n=45A018816
- Expansion of Product_{m >= 1} (1-m*q^m)^15.at n=6A022675
- n written in fractional base 4/2.at n=28A024630
- Position of n^3 + 9 in A024975.at n=26A024979
- a(n) = sum of the numbers between the two n's in A026354.at n=43A026357
- Number of partitions of n into an odd number of parts, the least being 4; also, a(n+4) = number of partitions of n into an even number of parts, each >=4.at n=56A027190
- Sequence satisfies T^2(a)=a, where T is defined below.at n=53A027584
- Convolution of Thue-Morse sequence A001285 with primes.at n=28A029888
- Numbers whose base-3 representation has 4 more 0's than 2's.at n=43A031456
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 22.at n=42A031520
- Numbers in which all pairs of consecutive base-9 digits differ by 3.at n=40A033080
- Numbers whose maximal base-10 run length is 3.at n=29A033284