918
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 2160
- Proper Divisor Sum (Aliquot Sum)
- 1242
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 288
- Möbius Function
- 0
- Radical
- 102
- Omega Function (Ω)
- 5
- 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
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 129
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- neunhundertachtzehn· ordinal: neunhundertachtzehnste
- English
- nine hundred eighteen· ordinal: nine hundred eighteenth
- Spanish
- novecientos dieciocho· ordinal: 918º
- French
- neuf cent dix-huit· ordinal: neuf cent dix-huitième
- Italian
- novecentodiciotto· ordinal: 918º
- Latin
- nongenti duodeviginti· ordinal: 918.
- Portuguese
- novecentos e dezoito· ordinal: 918º
Appears in sequences
- Numbers beginning with letter 'n' in English.at n=30A000981
- Shifts 3 places left under binomial transform.at n=12A000996
- Number of partitions of n into at most 5 parts.at n=33A001401
- Numbers k such that the k-th tetrahedral number is the sum of 2 tetrahedral numbers.at n=32A002311
- Smallest number of stones in Tchoukaillon (or Mancala, or Kalahari) solitaire that make use of n-th hole.at n=52A002491
- Self numbers divisible by sum of their digits (or, self numbers which are also Harshad numbers).at n=26A003219
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals rooted at a cell up to rotation and reflection.at n=16A003452
- Smallest positive integer that is n times its digit sum, or 0 if no such number exists.at n=50A003634
- Numbers that are a sum of distinct positive cubes in more than one way.at n=28A003998
- Powers of 2 written in base 15. (Next term contains a non-decimal character.)at n=11A004654
- Theta series of {E_6}* lattice.at n=8A005129
- Number of entries in first n rows of Pascal's triangle not divisible by 3.at n=70A006048
- Numbers k such that k^8 + 1 is prime.at n=37A006314
- Number of loopless rooted planar maps with 3 faces and n vertices and no isthmuses. Also a(n)=T(4,n-3), array T as in A049600.at n=14A006416
- Numbers k such that sigma(k+2) = sigma(k).at n=6A007373
- Coordination sequence T2 for Zeolite Code AET.at n=21A008008
- Coordination sequence T3 for Zeolite Code AET.at n=21A008009
- Coordination sequence T1 for Zeolite Code AFY.at n=25A008029
- Coordination sequence T1 for Zeolite Code EUO.at n=19A008095
- Coordination sequence T1 for Zeolite Code LIO.at n=21A008129