2130
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 6
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 5184
- Proper Divisor Sum (Aliquot Sum)
- 3054
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 560
- Möbius Function
- 1
- Radical
- 2130
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 76
- 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
- Expansion of 1/((1-x)^3*(1-x^2)^2*(1-x^3)).at n=15A002625
- Worst cases for Pierce expansions (numerators).at n=24A006537
- Coordination sequence T1 for Zeolite Code LIO.at n=32A008129
- Coordination sequence T1 for Zeolite Code LTN.at n=32A008140
- Number of ordered quadruples of integers from [ 1..n ] with no global factor.at n=13A015634
- a(n) = n*(19*n - 1)/2.at n=15A022276
- Place where n-th 1 occurs in A023127.at n=41A022789
- Convolution of A023532 and primes.at n=37A023606
- Convolution of Lucas numbers and odd numbers.at n=10A023620
- n written in fractional base 5/2.at n=45A024632
- a(n) = (1/C(n,0) - 1/C(n,1) + ... + d/C(n,k))*L, where d = (-1)^k,k = [ n/2 ], L = LCM{C(n,0), C(n,1),..., C(n,n)}.at n=11A025536
- Numbers k such that A174141(k) is divisible by k.at n=26A032581
- Concatenation of n and n + 9 or {n,n+9}.at n=20A032614
- a(n) = floor(T_(n+1)/T_(n)) where T_n is n-th tangential or "Zag" number (see A000182).at n=35A034972
- Positive numbers having the same set of digits in base 5 and base 10.at n=13A037433
- Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 2,1,3,0.at n=3A037743
- Base-4 palindromes that start with 2.at n=27A043004
- a(n) = (s(n)+1)/7, where s(n) = n-th base 7 palindrome that starts with 6.at n=26A043064
- a(n)=(s(n)+4)/8, where s(n)=n-th base 8 palindrome that starts with 4.at n=28A043068
- Numbers n such that string 2,2 occurs in the base 8 representation of n but not of n-1.at n=33A044205