4727
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4920
- Proper Divisor Sum (Aliquot Sum)
- 193
- 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
- 4536
- Möbius Function
- 1
- Radical
- 4727
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 59
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Coordination sequence T5 for Zeolite Code VNI.at n=42A009911
- a(0) = 1, a(n) = 21*n^2 + 2 for n>0.at n=15A010011
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly nine 1's.at n=12A020445
- Sum of squares of the first n primes.at n=11A024450
- Numbers k such that k^2 is palindromic in base 8.at n=32A029805
- Numbers k such that 29*2^k+1 is prime.at n=20A032364
- Write 1,2,... in a clockwise spiral; sequence gives numbers on positive x axis.at n=34A033951
- Numerators of continued fraction convergents to sqrt(131).at n=4A041238
- Numbers n such that 81*2^n-1 is prime.at n=16A050566
- a(1) = 1, a(2) = 3; for n>2, a(n) = least value > a(n-1) such that pairwise differences are unique.at n=48A051788
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 20.at n=35A051985
- a(1) = 1; a(n+1) = a(n) + (largest triangular number <= a(n)).at n=13A060985
- a(n) = floor(e^(n/e)).at n=23A061481
- Expansion of Product_{i in A069909} 1/(1 - x^i).at n=55A069911
- Average of terms in n-th row of A077529.at n=13A077532
- Let f(1)=f(2)=1, f(k)=f(k-1)+f(k-2)+ (k (mod n)). Then f(k)=floor(r(n)*F(k))+g(k) where F(k) denotes the k-th Fibonacci number and g(k) a function becoming periodic. Sequence depends on r(n) which is the largest positive root of : a(3n-2)*X^2-a(3n-1)*X+a(3n)=0.at n=40A081420
- a(n) = Sum_{2 <= p <= n, p prime} p^2.at n=39A081738
- a(n) = Sum_{2 <= p <= n, p prime} p^2.at n=38A081738
- a(n) = Sum_{2 <= p <= n, p prime} p^2.at n=37A081738
- a(n) = Sum_{2 <= p <= n, p prime} p^2.at n=36A081738