17929
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 17930
- 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
- 17928
- Möbius Function
- -1
- Radical
- 17929
- 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
- 216
- 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
- 2056
- 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 65.at n=18A020404
- a(n) = 5*a(n-1) - a(n-2) with a(0)=1, a(1)=7.at n=6A055271
- Primes p such that p and p^2 have same digit sum.at n=30A058370
- Smallest m such that A064672(m) = n.at n=25A064689
- a(1) = 7 then the smallest number such that the forward as well as the reverse n-th partial concatenation is a prime for n>1. (Reverse concatenation is taken term-wise and not digit-wise).at n=40A083994
- Primes for which the weight as defined in A117078 is 11 and the gap as defined in A001223 is 10.at n=22A119596
- G.f. satisfies: A(x) = A(A(x)) - x*A(A(A(x))), with A(0)=0.at n=9A120566
- Primes from A122136 corresponding to the indices A122138.at n=23A122139
- Primes congruent to 15 mod 53.at n=39A142545
- Primes congruent to 52 mod 59.at n=38A142779
- Primes congruent to 56 mod 61.at n=35A142854
- a(n) = 5*a(n-3) - a(n-6) with terms 1..6 as 0, 1, 2, 5, 7, 9.at n=19A142879
- Primes which are anagrams of cubes.at n=36A161854
- Primes p such that p plus or minus the sum of the fourth powers of its digits is a prime in both cases.at n=24A179595
- Number of nX7 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=3A207241
- T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=48A207242
- Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=6A207244
- The smallest of four consecutive primes with prime gaps {a,b,c} = {10,18,2}.at n=2A215719
- Number of nX5 0..2 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.at n=3A223996
- T(n,k)=Number of nXk 0..2 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.at n=31A223999