2154
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4320
- Proper Divisor Sum (Aliquot Sum)
- 2166
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 716
- Möbius Function
- -1
- Radical
- 2154
- 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
- 32
- 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
- Number of non-degenerate disjunctively-realizable functions of n variables.at n=4A005616
- Number of factors in the infinite word formed by the Kolakoski sequence A000002.at n=48A007782
- Coordination sequence T2 for Zeolite Code AFT.at n=35A008027
- Coordination sequence T7 for Zeolite Code EUO.at n=29A008102
- Coordination sequence T1 for Zeolite Code GME and AFX.at n=35A008110
- Coordination sequence T2 for Zeolite Code LTL.at n=34A008139
- Coordination sequence T1 for Zeolite Code YUG.at n=30A008247
- Coordination sequence for Cr3Si, Si position.at n=12A009927
- Powers of cube root of 10 rounded down.at n=10A018003
- Powers of cube root of 10 rounded to nearest integer.at n=10A018004
- Pisot sequence T(4,9), a(n) = floor(a(n-1)^2/a(n-2)).at n=8A019492
- a(n) = 3*a(n-1) - 4*a(n-3) + a(n-6).at n=8A019493
- Numbers k such that the continued fraction for sqrt(k) has period 24.at n=38A020363
- a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026648.at n=4A026974
- Dirichlet convolution of d(n) (# of divisors) with b_n=2^(n-1).at n=11A034771
- Number of partitions of n with equal number of parts congruent to each of 0 and 1 (mod 3).at n=38A035534
- Number of partitions of n with equal nonzero number of parts congruent to each of 0 and 1 (mod 5).at n=39A035562
- Number of partitions in parts not of the form 7k, 7k+2 or 7k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 2 are greater than 1.at n=40A035938
- Positive numbers having the same set of digits in base 8 and base 10.at n=12A037442
- a(n)=(s(n)+4)/8, where s(n)=n-th base 8 palindrome that starts with 4.at n=31A043068