2189
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2400
- Proper Divisor Sum (Aliquot Sum)
- 211
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1980
- Möbius Function
- 1
- Radical
- 2189
- 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
- 32
- 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
- Value of an urn with n balls of type -1 and n+2 balls of type +1.at n=5A003125
- Numbers that are the sum of 5 positive 6th powers.at n=15A003361
- Numbers that are the sum of 3 positive 7th powers.at n=4A003370
- a(n) = floor(Fibonacci(n)/5).at n=21A004698
- Numbers that are the sum of at most 5 nonzero 6th powers.at n=48A004856
- Numbers that are the sum of at most 3 positive 7th powers.at n=12A004865
- Numbers that are the sum of at most 4 positive 7th powers.at n=17A004866
- Numbers that are the sum of at most 5 positive 7th powers.at n=23A004867
- Numbers that are the sum of at most 6 positive 7th powers.at n=30A004868
- Numbers that are the sum of at most 7 positive 7th powers.at n=38A004869
- Numbers that are the sum of at most 8 positive 7th powers.at n=47A004870
- a(n) = floor(n*phi^11), where phi is the golden ratio, A001622.at n=11A004926
- a(n) = round(n*phi^11), where phi is the golden ratio, A001622.at n=11A004946
- Number of points on surface of square pyramid: 3*n^2 + 2 (n>0).at n=27A005918
- Expansion of (1+x^11)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=54A008772
- Coordination sequence T2 for Keatite.at n=26A009845
- Coordination sequence T7 for Zeolite Code CON.at n=33A009874
- a(0) = 1, a(n) = 27*n^2 + 2 for n>0.at n=9A010017
- f-vectors for simplicial complexes of dimension at most 2 on at most n-1 vertices.at n=9A011827
- f-vectors for 5-neighborly simplicial complexes on n+4 vertices.at n=4A011837