2146
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
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3420
- Proper Divisor Sum (Aliquot Sum)
- 1274
- 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
- 1008
- Möbius Function
- -1
- Radical
- 2146
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- no
- 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
- Nonsquare 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>0} Kronecker(D,k)/k.at n=24A003421
- Number of non-vanishing Feynman diagrams of order 2n for the electron or the photon propagators in quantum electrodynamics.at n=5A005411
- Coordination sequence T3 for Zeolite Code AEI.at n=35A008003
- Expansion of 1/(1-x^8-x^9-x^10-x^11-x^12-x^13-x^14-x^15-x^16).at n=52A017874
- Numbers k such that the continued fraction for sqrt(k) has period 21.at n=15A020360
- a(n) = a(n-1) + Sum_{k=0..n-4} a(k)*a(n-4-k), a(0) = 1. Generalized Catalan Numbers.at n=16A023426
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5,..., 1/(2n-1)} satisfy r < s, then r < k/m < s for some integer k.at n=37A024819
- 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 3.at n=29A031416
- a(n) = (2*n - 1)*(3*n + 1).at n=19A033569
- Coordination sequence T1 for Zeolite Code SBT.at n=37A033612
- Number of ways to partition a labeled set into 2-colored subsets of equal size.at n=9A038043
- a(n)=(s(n)+4)/8, where s(n)=n-th base 8 palindrome that starts with 4.at n=30A043068
- Numbers k such that string 5,4 occurs in the base 7 representation of k but not of k-1.at n=49A044177
- Numbers n such that string 4,2 occurs in the base 8 representation of n but not of n-1.at n=37A044221
- Numbers k such that the string 4,4 occurs in the base 9 representation of k but not of k-1.at n=26A044291
- Numbers n such that string 4,6 occurs in the base 10 representation of n but not of n-1.at n=23A044378
- Numbers n such that string 4,2 occurs in the base 8 representation of n but not of n+1.at n=37A044602
- Numbers n such that string 4,4 occurs in the base 9 representation of n but not of n+1.at n=26A044672
- Numbers n such that string 4,6 occurs in the base 10 representation of n but not of n+1.at n=23A044759
- Numbers whose base-4 representation contains exactly two 0's and three 2's.at n=23A045050