2138
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3210
- Proper Divisor Sum (Aliquot Sum)
- 1072
- 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
- 1068
- Möbius Function
- 1
- Radical
- 2138
- 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
- 24
- 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
- yes
- Odd
- no
Appears in sequences
- Smallest k such that the product of q/(q-1) over the primes from prime(n) to prime(n+k-1) is greater than 2.at n=31A001276
- Series for second perpendicular moment of square lattice.at n=9A006734
- Coordination sequence T1 for Zeolite Code APC.at n=32A008032
- Coordination sequence T2 for Zeolite Code DAC.at n=29A008068
- Coordination sequence T2 for Zeolite Code EPI.at n=29A008091
- If a, b in sequence, so is ab+6.at n=24A009307
- Numbers k such that the continued fraction for sqrt(k) has period 5.at n=44A010337
- Number of 3's in partitions of n into distinct parts.at n=52A015737
- Number of partitions of n into distinct parts, none being 3.at n=50A015745
- Place where n-th 1 occurs in A023117.at n=43A022779
- a(n) = 3^n - n^2.at n=7A024025
- a(n) = Sum_{k=0..n} (k+1) * A026769(n, k).at n=8A027243
- Expansion of Product(1+q^m)^(m(m-1)/2); m=1..inf.at n=13A027999
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 5.at n=14A031418
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 4.at n=31A031428
- Multiplicity of highest weight (or singular) vectors associated with character chi_79 of Monster module.at n=35A034467
- Even numbers k such that b(k) is greater than b(k-1) and b(k+1); b(k) = A033178(k).at n=30A038007
- Number of partitions with at most one part divisible by 5.at n=25A039905
- Denominators of continued fraction convergents to sqrt(519).at n=9A041993
- Base-5 palindromes that start with 3.at n=22A043008