13679
domain: N
Properties
Digital Properties
- Digit Count
- 5
- 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
- 13680
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13678
- Möbius Function
- -1
- Radical
- 13679
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 63
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1615
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has period 92.at n=33A020431
- Increasing gaps among twin primes: the smallest prime of the second twin pair.at n=10A036062
- a(n) contains the digit b-1 in all bases b from 2 to n.at n=12A051640
- a(n) contains the digit b-1 in all bases b from 2 to n.at n=14A051640
- a(n) contains the digit b-1 in all bases b from 2 to n.at n=13A051640
- Endpoints for runs of consecutive primes mentioned in A054691.at n=7A054692
- Numbers k such that A055079(k) = 2^k.at n=32A057838
- Primeval numbers: numbers that set a record for the number of distinct primes that can be obtained by permuting some subset of their digits.at n=22A072857
- Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d=2,4 or 6) and forming d-pattern=[2,6,4]; short d-string notation of pattern = [264].at n=18A078848
- Primes p such that the differences between the 5 consecutive primes starting with p are (2,6,4,2).at n=8A078948
- Near twin primes of order 12: twin primes p,p+2 such that p+12 and p+14 are primes.at n=38A079292
- Smallest member of a pair of consecutive twin prime pairs that have one prime between them.at n=42A089629
- a(n) = lesser of a pair of twin primes p, q=p+2 such that product of first n primes plus p is a prime and also product of first n primes plus q is a prime.at n=32A090795
- Least initial value for a Euclid/Mullin sequence whose 3rd term (= least prime divisor of 1+2p) equals the n-th prime. prime(1)=2 is never a third term, so offset=2.at n=27A094464
- Primes prime(k) such that (prime(k-1) + prime(k+1) + prime(k+2))/prime(k) = 3.at n=25A094933
- Numbers k such that k^4 = x^3 + y^2 has an integer solution.at n=36A096741
- Value of C in y = x^2+7x+C such that y is prime for all x = 0 to 4.at n=20A097436
- Primes p such that p + 2 and p*(p + 2) + 2 are primes.at n=27A108013
- Smallest number which does not use digit n-1 written in base n, but does use digit b-1 written in base b for any 1<b<n.at n=15A119354
- Primeval primes: primes in A072857.at n=12A119535