2647
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2648
- 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
- 2646
- Möbius Function
- -1
- Radical
- 2647
- 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
- 53
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 383
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Largest prime == 7 (mod 8) with class number 2n+1.at n=7A002147
- Coordination sequence T1 for Zeolite Code DAC.at n=32A008067
- Coordination sequence T2 for Zeolite Code GOO.at n=35A008112
- Coordination sequence T2 for Zeolite Code STI.at n=35A008235
- a(0) = 1, a(n) = 5*n^2 + 2 for n>0.at n=23A010001
- Numerator of [x^(2n+1)] in the Taylor series tan(cosec(x)-cosech(x)) = x/3 +x^3/81 +949*x^5/204120 +2647*x^7/5511240+... .at n=3A013532
- Smallest positive number that can be written as sum of distinct Fibonacci numbers in n ways.at n=36A013583
- Numbers k such that the k-th Euclid number A006862(k) = 1 + (Product of first k primes) is prime.at n=17A014545
- Numbers k such that the continued fraction for sqrt(k) has period 52.at n=6A020391
- Primes that remain prime through 2 iterations of function f(x) = 2x + 3.at n=40A023242
- Primes that remain prime through 2 iterations of function f(x) = 4x + 9.at n=43A023251
- Primes that remain prime through 2 iterations of function f(x) = 9x + 10.at n=45A023268
- Primes that remain prime through 3 iterations of function f(x) = 9x + 10.at n=16A023299
- Primes that are palindromic in base 7.at n=10A029975
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 51.at n=3A031549
- Lucky numbers with size of gaps equal to 12 (upper terms).at n=34A031895
- a(n) = prime(9*n - 4).at n=42A031904
- a(n) = prime(10*n-7).at n=38A031917
- Lower prime of a difference of 10 between consecutive primes.at n=35A031928
- Upper prime of a difference of 14 between consecutive primes.at n=13A031933