4421
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 4422
- 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
- 4420
- Möbius Function
- -1
- Radical
- 4421
- 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
- 95
- 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
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 601
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes of the form k^2 - k - 1.at n=37A002327
- Alternating factorials: n! - (n-1)! + (n-2)! - ... 1!.at n=7A005165
- Coordination sequence T7 for Zeolite Code EUO.at n=41A008102
- a(n) = floor( n*(n-1)*(n-2)/25 ).at n=49A011907
- Molien series of 4-dimensional representation of u.g.g.r. #8.at n=21A013978
- Numbers k such that the continued fraction for sqrt(k) has period 13.at n=28A020352
- Upper prime of a difference of 12 between consecutive primes.at n=43A031931
- Exactly 5 digits from {1,2,3,4,5,6,7,8,9} can precede a(n) to form a prime.at n=37A032695
- a(n) = floor( (Pi/e)^n ).at n=58A032739
- Base-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,0,1.at n=6A033122
- Primes of form x^2+65*y^2.at n=31A033241
- a(n)=number of Gaussian integers z=a+bi satisfying |z|<=n+1/2.at n=37A036704
- Sums of 5 distinct powers of 4.at n=8A038473
- Smallest k>1 such that k(p-1)-1 is divisible by p^2, p=n-th prime.at n=18A039914
- Numerators of continued fraction convergents to sqrt(553).at n=5A042058
- Primes of the form n*phi(n)-1 where phi is the Euler function (in order of appearance).at n=31A046078
- a(n)=T(n,n+1), array T as in A049735.at n=26A049741
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 23.at n=10A051964
- a(n)=[A*a(n-1)+B*a(n-2)+C]/p^r, where p^r is the highest power of p dividing [A*a(n-1)+B*a(n-2)+C], A=1.0001, B=1.0001, C=1.5, p=2.at n=33A053522
- Prime number spiral (clockwise, Southwest spoke).at n=12A054568