2137
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2138
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 2136
- Möbius Function
- -1
- Radical
- 2137
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 63
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 322
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers n such that (10^n + 1)/11 is a prime.at n=8A001562
- Number of partitions of 3n into n parts from the set {0, 1, ..., 6} (repetitions admissible).at n=16A001977
- Expansion of g.f.: (1+x^3)*(1+x^4)/((1-x)*(1-x^2)^2*(1-x^4)).at n=36A004657
- Primes p such that (p+1)/2 is prime.at n=36A005383
- 3 and -3 are both 4th powers (one implies other) mod these primes p=1 mod 8.at n=14A014755
- Numbers k such that the continued fraction for sqrt(k) has period 59.at n=0A020398
- Initial members of prime triples (p, p+4, p+6).at n=27A022005
- Primes that remain prime through 2 iterations of function f(x) = 5x + 2.at n=29A023252
- Primes that remain prime through 2 iterations of function f(x) = 9x + 4.at n=32A023266
- Primes that remain prime through 2 iterations of function f(x) = 10x + 9.at n=38A023270
- Primes that remain prime through 3 iterations of function f(x) = 3x + 10.at n=17A023280
- Primes that remain prime through 3 iterations of function f(x) = 5x + 2.at n=6A023283
- Primes that remain prime through 3 iterations of function f(x) = 10x + 9.at n=12A023301
- Primes that remain prime through 4 iterations of function f(x) = 3x + 10.at n=6A023310
- s(n+3)/2, where s is A024945.at n=13A024946
- a(n) = (d(n)-r(n))/2, where d = A026046 and r is the periodic sequence with fundamental period (0,1,0,1).at n=19A026047
- Friedlander-Iwaniec primes: Primes of form a^2 + b^4.at n=44A028916
- a(n) = prime(9*n - 2).at n=35A031383
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 28 ones.at n=4A031796
- a(n) = prime(8*n - 6).at n=40A031912