8018
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 12720
- Proper Divisor Sum (Aliquot Sum)
- 4702
- 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
- 3780
- Möbius Function
- -1
- Radical
- 8018
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 158
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- a(n) = Sum_{k=3..n} (k-1)!*C(n,k)/2.at n=8A002807
- a(n) = n OR n^3 (applied to ternary expansions).at n=19A008469
- Coordination sequence for Ni2In, Position Ni1 and In.at n=27A009941
- Conjectured formula for irreducible 5-fold Euler sums of weight 2n+13.at n=37A019450
- 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 88.at n=20A031586
- Number of partitions of n into parts not of the form 13k, 13k+4 or 13k-4. Also number of partitions with at most 3 parts of size 1 and differences between parts at distance 5 are greater than 1.at n=36A035952
- Numbers having three 8's in base 9.at n=33A043487
- Numbers whose base-6 representation has exactly 6 runs.at n=17A043614
- a(n) = a(n-1) + a(m) for n >= 3, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = 3.at n=42A050069
- Numbers k such that k^8 == 1 (mod 9^3).at n=21A056084
- Smallest multiple of the n-th prime beginning and ending in n with a(1)=a(3)=0.at n=7A078212
- A bisection of A002807.at n=3A099198
- Numbers k such that k*(k+6) gives the concatenation of two numbers m and m-1.at n=1A116282
- Bond series for second perpendicular moment of hexagonal net.at n=18A120544
- a(n) = 6^n + 3^n - 1.at n=5A155604
- a(n) = 729*n - 1.at n=10A158395
- Collatz (or 3x+1) trajectory starting at 703.at n=12A161021
- a(n) = 11*3^n-1.at n=6A198646
- a(n) = 11*9^n-1.at n=3A198968
- Nearest integer to 100*1.1^n.at n=46A204590