2141
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2142
- 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
- 2140
- Möbius Function
- -1
- Radical
- 2141
- 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
- 24
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 323
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Smallest nonnegative number that is the sum of 3 squares in exactly n ways.at n=19A000437
- Smallest number that is the sum of 3 squares in at least n ways.at n=19A000451
- Number of primes < prime(n)^2.at n=32A000879
- Values of m in the discriminant D = -4*m leading to a new maximum of the L-function of the Dirichlet series L(1) = Sum_{k=1..oo} Kronecker(D,k)/k.at n=16A003420
- Generalized Fibonacci numbers.at n=6A006603
- Where the prime race among 7k+1, ..., 7k+6 changes leader.at n=19A007354
- Coordination sequence T2 for Zeolite Code APC.at n=32A008033
- Coordination sequence T4 for Zeolite Code -PAR.at n=33A009858
- Numbers k such that the continued fraction for sqrt(k) has period 31.at n=4A020370
- Place where n-th 1 occurs in A023123.at n=39A022785
- Primes that remain prime through 2 iterations of function f(x) = 4x + 9.at n=39A023251
- Primes that remain prime through 2 iterations of the function f(x) = 5x + 4.at n=22A023253
- Primes that remain prime through 3 iterations of function f(x) = 5x + 4.at n=8A023284
- Primes that remain prime through 4 iterations of function f(x) = 5x + 4.at n=2A023314
- Number of 10's in all partitions of n.at n=34A024794
- a(n) is the smallest number that is the sum of 3 nonzero squares in exactly n ways.at n=18A025414
- Least sum of 3 distinct nonzero squares in exactly n ways.at n=18A025415
- Index of 6^n within the sequence of the numbers of the form 2^i*6^j.at n=40A025712
- Primes in which parity of digits alternates.at n=51A030144
- a(n) = prime(9n-1).at n=35A031375