17581
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 17582
- 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
- 17580
- Möbius Function
- -1
- Radical
- 17581
- 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
- 128
- 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
- 2022
- 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 85.at n=16A020424
- Least prime in A031934 (lesser of 16-twins) whose distance to the next 16-twin is 6*n.at n=19A052357
- Pseudo-random numbers: Davenport's generator for 32-bit integers.at n=27A084277
- a(n) = n^3 + 5.at n=26A084381
- For n >= 2, a(n+1)=prime[prime[a(n)]-n]; a(1)=2.at n=5A106047
- Primes p such that p + googol is prime.at n=12A108250
- Primes in A132286.at n=42A132287
- Primes congruent to 38 mod 53.at n=38A142568
- Primes congruent to 58 mod 59.at n=30A142785
- Primes congruent to 13 mod 61.at n=36A142811
- Primes p, with index k, such that p-k and p+k are both prime.at n=28A143794
- Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 0110-1111 pattern in any orientation.at n=10A146384
- Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 0110-1111 pattern in any orientation.at n=22A146386
- Primes which are triangular numbers plus 3.at n=18A159047
- Primes of the form k^3 + 5.at n=5A201260
- Number of involutions avoiding the pattern 21 (with a dot over the 1).at n=11A201689
- 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=22A216590
- Primes p such that p = 361 + 420*k for some k.at n=17A217656
- Fundamental discriminants d uniquely characterizing all complex biquadratic fields Q(sqrt(-3),sqrt(d)) which have 3-class group of type (3,3) and second 3-class group isomorphic to SmallGroup(729,37).at n=10A250240
- Primes of form x^2 - phi(x) in increasing order.at n=11A258435