4921
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 6080
- Proper Divisor Sum (Aliquot Sum)
- 1159
- 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
- 3888
- Möbius Function
- -1
- Radical
- 4921
- 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
- 72
- 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
- no
- Odd
- yes
Appears in sequences
- Hex (or centered hexagonal) numbers: 3*n*(n+1)+1 (crystal ball sequence for hexagonal lattice).at n=40A003215
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals up to rotation.at n=36A003451
- Sum of cubes of primes dividing n.at n=33A005064
- Sum of cubes of primes = 2 mod 3 dividing n.at n=33A005076
- Sum of cubes of primes = 2 mod 3 dividing n.at n=67A005076
- Coordination sequence T3 for Zeolite Code MEL.at n=45A008152
- Number of 5-dimensional centered tetrahedral numbers.at n=9A008499
- a(n) = (1 - (-3)^n)/4.at n=9A014983
- Triangle of q-binomial coefficients for q=-3.at n=46A015110
- Gaussian binomial coefficient [ n,8 ] for q=-3.at n=1A015357
- a(n) = 2*a(n-1) + 3*a(n-2), with a(0)=0, a(1)=1.at n=9A015518
- Pseudoprimes to base 11.at n=19A020139
- Pseudoprimes to base 26.at n=33A020154
- Pseudoprimes to base 27.at n=34A020155
- Pseudoprimes to base 31.at n=25A020159
- Pseudoprimes to base 45.at n=32A020173
- Pseudoprimes to base 75.at n=30A020203
- Pseudoprimes to base 88.at n=27A020216
- Strong pseudoprimes to base 27.at n=8A020253
- Numbers k such that the continued fraction for sqrt(k) has period 48.at n=39A020387