13859
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
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 13860
- 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
- 13858
- Möbius Function
- -1
- Radical
- 13859
- 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
- 151
- 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
- 1637
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Smallest prime p==3 (mod 8) such that Q(sqrt(-p)) has class number 2n+1.at n=33A002148
- Number of polynomials of height n: a(1)=1, a(2)=1, a(3)=4, a(n) = 2*a(n-1) + a(n-2) + 2 for n >= 4.at n=11A005409
- Knopfmacher expansion of 2/3: a(n+1) = a(n-1)(a(n)+1)-1.at n=6A007568
- Numbers k such that the continued fraction for sqrt(k) has period 90.at n=31A020429
- Primes that remain prime through 3 iterations of function f(x) = 3x + 2.at n=13A023277
- Primes that remain prime through 4 iterations of function f(x) = 3x + 2.at n=4A023307
- Multiplicity of highest weight (or singular) vectors associated with character chi_98 of Monster module.at n=42A034486
- Least prime in A031932 (lesser of 14-twins) whose distance to the next 14-twin is 6*n.at n=30A052356
- Second term of strong prime 5-tuples: p(m)-p(m-1) > p(m+1)-p(m) > p(m+2)-p(m+1) > p(m+3)-p(m+2).at n=32A054809
- a(n) is the least k > 0 such that sigma(k!) >= n*k!.at n=17A061556
- Table read by rows where i-th row consists of primes P of the form P=j*P(i)# -1 or P=j*P(i)# +1 with 0 < j < P(i+1). Here P(r)# = A002110.at n=37A087715
- Primes p such that tau(p-1)+tau(p+1) is larger than for any previous term. (Smallest prime sandwiched between more composite numbers.)at n=26A090481
- Smallest number m such that m#/phi(m#) >= n, where m# indicates the primorial (A034386) of m and phi is Euler's totient function.at n=16A091440
- Highly cototient numbers that are prime, or intersection of A000040 and A100827.at n=33A105440
- Smallest prime a such that (a*b)^2 + a*b -1 is prime with b prime = 2^(2*n) - 2^n - 1, see A098845 for n.at n=28A107639
- Chen primes p such that p + 2 is triangular.at n=11A109504
- Positive integers i for which A112049(i) == 8.at n=12A112068
- a(n) = a(n-1) + 2*n^2 with a(1) = 1.at n=26A112524
- a(n) = A126098(n) - 1.at n=20A117010
- Primes for which the weight as defined in A117078 is 15 and the gap as defined in A001223 is 14.at n=20A118380