8747
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8748
- 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
- 8746
- Möbius Function
- -1
- Radical
- 8747
- 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
- 47
- 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
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1091
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Class 1+ primes: primes of the form 2^i*3^j - 1 with i, j >= 0.at n=25A005105
- a(n) = a(n-1) + a(n - 1 - number of even terms so far).at n=41A006336
- If x and y are terms, so is x*y + 9.at n=40A009350
- Primes of the form k^2 + k + 5.at n=28A027755
- 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 93.at n=10A031591
- Numbers whose set of base-7 digits is {3,4}.at n=39A032831
- Numbers having three 8's in base 9.at n=34A043487
- Discriminants of imaginary quadratic fields with class number 21 (negated).at n=27A046018
- Primes p from A031924 such that A052180(primepi(p)) = 13.at n=14A052233
- Numbers k such that k^8 == 1 (mod 9^3).at n=23A056084
- Let prime(i) = i-th prime, let twin(n) = (P,Q) be n-th pair of twin primes; sequence gives prime(P).at n=39A057470
- Number of alpha-beta evaluations in a tree of depth n and branching factor b=3.at n=15A060647
- Primes which, although they have correct parity, are not in the prime number maze.at n=6A065123
- Primes of the form sum 6d/(2 + mu(d)) for some k and all d dividing k.at n=23A069548
- Number of primes less than 10^n with initial digit 4.at n=5A073514
- Group successively larger prime numbers so that the sum of the n-th group is a multiple of n. Sequence gives the first term of each group.at n=44A074129
- Smallest prime factor of googol - n that exceeds 13, or 1 if googol - n is 13-smooth.at n=11A078813
- a(1) = 7 then the smallest number such that the forward as well as the reverse n-th partial concatenation is a prime for n>1. (Reverse concatenation is taken term-wise and not digit-wise).at n=20A083994
- Primes p such that p-3 and p+3 are divisible by a cube.at n=8A089201
- p(k) such that 2*p(k)+3 and 2*p(k+1) + 3 are consecutive primes, where p(i) denotes the i-th prime.at n=34A089527