4687
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4840
- Proper Divisor Sum (Aliquot Sum)
- 153
- 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
- 4687
- 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
- 152
- 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
- Numbers k such that 5*2^k + 1 is prime.at n=13A002254
- Values of m in the discriminant D = -4*m leading to a new minimum of the L-function of the Dirichlet series L(1) = Sum_{k>=1} Kronecker(D,k)/k.at n=5A003521
- Sum_{T(i,j)}, 0<=j<=i, 0<=i<=n, where T is the array in A026386.at n=9A026396
- Numbers having period-6 5-digitized sequences.at n=29A031190
- Number of increasing asymmetric rooted polygonal cacti with bridges (mixed Husimi trees).at n=6A035357
- Numbers whose maximal base-8 run length is 4.at n=14A037995
- Numbers having four 1's in base 8.at n=10A043428
- a(n) = (3*5^n - 1)/2.at n=5A057651
- Number of primes below n^3 does not exceed n times the number of primes below n^2.at n=43A060304
- Numbers k such that sigma(phi(sigma(k))) = phi(k).at n=9A066465
- Numbers k such that sigma(k) divides sigma(phi(k)).at n=25A066831
- Numbers n such that sigma(phi(n))/sigma(n) = 3.at n=3A067383
- Numbers k such that k and 3^k end with the same two digits.at n=46A067749
- Square array read by antidiagonals of base n numbers written as 122...222 with k 2's (and a suitable interpretation for n=0, 1 or 2).at n=60A067763
- a(n) = 4*n^2 + 10*n + 1.at n=33A082112
- Square array of numbers read by antidiagonals where T(n,k) = ((k+3)*(k+2)^n-2)/(k+1).at n=41A090842
- a(n) = Sum_{k=0..n} C(floor((n+1)/2),floor((k+1)/2))*2^k.at n=10A097162
- Leading diagonal of A100781.at n=42A100783
- Numerator of Sum_{k=1..n} 1/tau(k), where tau(k) is the number of divisors function.at n=39A104528
- G.f.: Product_{j>=1} Product_{i>=1} (1 + x^(i*j)).at n=22A107742