17851
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
- 17852
- 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
- 17850
- Möbius Function
- -1
- Radical
- 17851
- 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
- 71
- 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
- 2047
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes that remain prime through 3 iterations of function f(x) = 9x + 4.at n=34A023297
- Primes that remain prime through 4 iterations of function f(x) = 9x + 4.at n=11A023325
- Discriminants of imaginary quadratic fields with class number 23 (negated).at n=35A046020
- a(n) = prime(2^n - 1).at n=10A051438
- Primes p such that p-12, p and p+12 are consecutive primes.at n=13A053072
- a(n) = 10*n^2 + 5*n + 1.at n=42A080860
- Leading diagonal of triangle A093922.at n=41A093923
- Numbers k such that (273*2^k+1)^2-2 is prime.at n=28A100914
- Consider the array T(n, m) = m-th prime of the form n*i(i+1)/2 +/- 1. This sequence is the main diagonal.at n=29A125765
- Mother primes of order 8.at n=32A136067
- Penta-Primes. Prime Numbers n as a Sum of 5 consecutive prime numbers (four twin primes and single prime number in between) are primes.at n=9A138397
- Primes congruent to 43 mod 53.at n=37A142573
- Primes congruent to 33 mod 59.at n=36A142760
- Primes congruent to 39 mod 61.at n=29A142837
- Primes in A005891 = Centered pentagonal numbers: (5n^2 + 5n + 2)/2.at n=15A145838
- Greater of two consecutive primes, p < q, such that both p*q+p-q and p*q-p+q are prime numbers.at n=25A154552
- Primes p0 such that p0+p1+p2-+2 are primes; p0,p1,p2 are three consecutive primes.at n=20A158351
- Smallest primes p = p(k) with (p(k)+p(k+1)+p(k+2))/15 an integer.at n=12A168556
- a(n) = Sum_{k=0..n} C(3n+k,n-k)*C(4n-k,k).at n=4A184553
- Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of the symmetric matrix A202674 based on (1,3,5,7,9,...); by antidiagonals.at n=37A202675