818
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1230
- Proper Divisor Sum (Aliquot Sum)
- 412
- 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
- 408
- Möbius Function
- 1
- Radical
- 818
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 41
- Smith 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
Names
- German
- achthundertachtzehn· ordinal: achthundertachtzehnste
- English
- eight hundred eighteen· ordinal: eight hundred eighteenth
- Spanish
- ochocientos dieciocho· ordinal: 818º
- French
- huit cent dix-huit· ordinal: huit cent dix-huitième
- Italian
- ottocentodiciotto· ordinal: 818º
- Latin
- octingenti duodeviginti· ordinal: 818.
- Portuguese
- oitocentos e dezoito· ordinal: 818º
Appears in sequences
- Strobogrammatic numbers: the same upside down.at n=14A000787
- Numbers beginning with letter 'e' in English.at n=31A000873
- Number of 3-line partitions of n.at n=12A000991
- Smallest k such that the product of q/(q-1) over the primes from prime(n) to prime(n+k-1) is greater than 2.at n=20A001276
- Prime numbers of measurement.at n=27A002049
- Numbers k such that 39*2^k + 1 is prime.at n=24A002269
- Numbers k such that the k-th tetrahedral number is the sum of 2 tetrahedral numbers.at n=29A002311
- Numerators of double sums of reciprocals.at n=3A002429
- Number of coprime chains with largest member n.at n=58A003139
- Number of coprime chains with largest member prime(n).at n=16A003140
- Number of blobs with 2n+1 edges.at n=5A003168
- From a nim-like game.at n=24A003413
- Convolution of A002024 with itself.at n=31A004797
- Numbers with mirror symmetry about middle.at n=9A006072
- Horizontally symmetric numbers.at n=55A007284
- Coordination sequence T1 for Zeolite Code AFS.at n=22A008023
- Coordination sequence T1 for Zeolite Code BPH.at n=22A008055
- Coordination sequence T2 for Zeolite Code JBW.at n=19A008122
- Coordination sequence T7 for Zeolite Code MFS.at n=18A008179
- Expansion of e.g.f. sin(x)/cosh(log(1+x)).at n=7A009557