17189
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
- 17190
- 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
- 17188
- Möbius Function
- -1
- Radical
- 17189
- 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
- 27
- 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
- 1979
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of bipartite partitions.at n=17A002767
- a(n) = Sum_{m=1..n} Sum_{k=1..m} prime(k).at n=30A014148
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 15.at n=10A031603
- Numbers whose base-7 representation has exactly 6 runs.at n=28A043621
- Suppose p and q = p+20 are primes. Define the difference pattern of (p,q) to be the successive differences of the primes in the range p to q. There are 56 possible difference patterns, shown in the Comments line. Sequence gives smallest value of p for each difference pattern, sorted by magnitude.at n=53A079020
- Near twin primes of order 18: twin primes (p, p+2) such that p+18 and p+20 are primes.at n=27A079304
- "Secondary twin primes": a(n) = A006450(A096477(n)).at n=40A096479
- Primes of the form Sum[ Sum[ Prime[k], {k,1,m} ], {m,1,n} ] = A014148[n].at n=6A122382
- Primes congruent to 17 mod 53.at n=41A142547
- Primes congruent to 20 mod 59.at n=35A142747
- Primes congruent to 48 mod 61.at n=31A142846
- Primes p with property that there exists a number d>0 such that numbers p-k*d, k=1...7, are seven primes.at n=21A216590
- Primes q = 4*p+1, where p == 2 (mod 5) is also prime.at n=31A221981
- Primes p for which p^2 + p - 1 = q*r (q<r) such that q, r, p^2 + q - 1 and p^2 + r - 1 are primes.at n=49A227276
- Primes p such that p+2 and p^3+2 are also prime.at n=40A240110
- Number of nX5 0..1 arrays with every element equal to 0, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=6A302457
- T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=61A302460
- Number of 7Xn 0..1 arrays with every element equal to 0, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=4A302465
- The positive odd numbers x such that x = c^2 - y and +-x = a +- y, where (a,b,c) is a primitive Pythagorean triple (PPT), a is odd and y is an even positive integer.at n=29A357535
- a(0) = 1; a(n) = Sum_{k=0..n-1} (1 + k) * (1 + k^3) * binomial(n-1,k) * a(k) * a(n-1-k).at n=4A385940