8158
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12240
- Proper Divisor Sum (Aliquot Sum)
- 4082
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4078
- Möbius Function
- 1
- Radical
- 8158
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 65
- Smith Number
- yes
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Eleven iterations of Reverse and Add are needed to reach a palindrome.at n=20A015992
- Numbers k such that the continued fraction for sqrt(k) has period 100.at n=11A020439
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 90.at n=3A031588
- Numbers which need eleven 'Reverse and Add' steps to reach a palindrome.at n=19A065216
- Good examples of Hall's conjecture: integers x such that 0 < |x^3 - y^2| < sqrt(x) for some integer y.at n=2A078933
- Number of unrooted maps with n edges of (orientable) genus 3.at n=1A104596
- a(n) is the n-th J_20-prime (Josephus_20 prime).at n=10A163800
- Numerator of A166100(A166101(n))/A166102(n).at n=24A166272
- Number of symmetry classes of reduced 3 X 3 magilatin squares with largest entry n.at n=45A174019
- Numbers n such that 10^n - 99 is prime.at n=13A178439
- Values x for records of minima of positive distance d between a square cubefree integer y and a cube of positive and squarefree integer x and such d = y^2 - x^3.at n=4A179108
- Smallest k such that k^3 + 17 is divisible by 3^n.at n=9A212328
- Smallest k such that k^3 + 17 is divisible by 3^n.at n=10A212328
- Consider the ordered Goldbach partitions of the even numbers m. Then a(n) is the least m which contains prime(n) such partitions composed of odd primes.at n=39A216047
- Number of nonnegative solutions to x^3 + y^3 + z^3 <= n^3.at n=22A224215
- Cardinalities of the sub-operad FF_6 of the operad MFF.at n=4A231690
- Number of partitions p of n such that (number of numbers in p having multiplicity > 1) = number of 1s in p.at n=42A241090
- a(0) = 4; for n>0, a(n) = a(n-1) + 2^n - 3.at n=12A249453
- Indices of squares of primes in A098550.at n=24A251240
- Indices of the start of 9 successive distinct digits in the decimal expansion of Pi.at n=25A258158