2133
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3200
- Proper Divisor Sum (Aliquot Sum)
- 1067
- 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
- 1404
- Möbius Function
- 0
- Radical
- 237
- Omega Function (Ω)
- 4
- 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
- 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
- no
- Odd
- yes
Appears in sequences
- Octagonal numbers: n*(3*n-2). Also called star numbers.at n=27A000567
- Numbers k such that k, k+1 and k+2 have the same number of divisors.at n=41A005238
- Number of free binary trees admitting height n.at n=3A005588
- Positions of remoteness 5 in Beans-Don't-Talk.at n=44A005697
- Hyperperfect numbers: k = m*(sigma(k) - k - 1) + 1 for some m > 1.at n=7A007592
- 2-hyperperfect numbers: n = 2*(sigma(n) - n - 1) + 1.at n=1A007593
- Coordination sequence T4 for Zeolite Code EMT.at n=38A008089
- Coordination sequence T1 for Zeolite Code NON.at n=28A008212
- Odd octagonal numbers: (2n+1)*(6n+1).at n=13A014641
- Integer part of Gamma(n+7/10)/Gamma(7/10).at n=7A020061
- Pseudoprimes to base 80.at n=21A020208
- n written in fractional base 5/2.at n=48A024632
- Number of distinct products i*j*k with 1 <= i < j < k <= n.at n=32A027430
- Number of pairs of minimal vectors in n-dimensional lattice Kappa_n.at n=17A028926
- a(n) = (prime(n)-1)*(prime(n)-5)/12.at n=35A030006
- Numbers k such that 53*2^k+1 is prime.at n=12A032376
- Quotients k*(k+1)*(k+2) / (k+(k+1)+(k+2)) that are lucky numbers.at n=9A032792
- Hyperperfect numbers: x such that x = 1 + k*(sigma(x)-x-1) for some k > 0.at n=10A034897
- Limit of the position of the n-th partition into parts 5k+2 or 5k+3 in the list of all integer partitions sorted in reverse lexicographic order, for integers == 2 (mod 5).at n=47A035407
- Limit of the position of the n-th partition into parts 5k+2 or 5k+3 in the list of all integer partitions sorted in reverse lexicographic order, for integers == 3 (mod 5).at n=36A035408