8749
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9436
- Proper Divisor Sum (Aliquot Sum)
- 687
- 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
- 8064
- Möbius Function
- 1
- Radical
- 8749
- 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
- 78
- 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 that are the sum of 5 positive 7th powers.at n=18A003372
- Positions where A007600 increases.at n=25A007601
- Pseudoprimes to base 42.at n=24A020170
- Pseudoprimes to base 58.at n=35A020186
- Strong pseudoprimes to base 58.at n=11A020284
- a(n) = floor(4th elementary symmetric function of Sum_{j=1..k} 1/j, k = 1,2,...,n).at n=7A025214
- a(n) = T(3n,n), where T is the array defined in A025564.at n=5A025571
- The 5x + 1 sequence beginning at 7.at n=33A028389
- Numbers ending with '9' that are the difference of two positive cubes.at n=31A038864
- Numerators of continued fraction convergents to sqrt(42).at n=5A041070
- Numerators of continued fraction convergents to sqrt(168).at n=5A041310
- Numerators of continued fraction convergents to sqrt(378).at n=7A041716
- 5-morphic but not bimorphic, automorphic nor trimorphic.at n=43A056036
- Numbers k such that k^8 == 1 (mod 9^3).at n=24A056084
- Numbers k such that k^14 == 1 (mod 15^3).at n=10A056087
- Numbers n such that sigma(n)^2 - phi(n)^2 is a perfect square.at n=28A057654
- Numbers k such that (k+1)*phi(k) is a perfect square.at n=16A069952
- Non-palindromic n and its digit reversal have the same sum of prime factors (with repetition).at n=28A085607
- Triangular array T of numbers generated by these rules: 2 is in T; and if x is in T, then 2x-1 and 3x-2 are in T.at n=52A094617
- Chebyshev T-polynomials T(n,13) with Diophantine property.at n=3A097308