678
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 1368
- Proper Divisor Sum (Aliquot Sum)
- 690
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 224
- Möbius Function
- -1
- Radical
- 678
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 51
- Smith 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
Names
- German
- sechshundertachtundsiebzig· ordinal: sechshundertachtundsiebzigste
- English
- six hundred seventy-eight· ordinal: six hundred seventy-eighth
- Spanish
- seiscientos setenta y ocho· ordinal: 678º
- French
- six cent soixante-dix-huit· ordinal: six cent soixante-dix-huitième
- Italian
- seicentosettantotto· ordinal: 678º
- Latin
- sescenti septuaginta octo· ordinal: 678.
- Portuguese
- seiscentos e setenta e oito· ordinal: 678º
Appears in sequences
- Decimal concatenation of n, n+1, and n+2.at n=6A001703
- a(n) = least value of m for which Liouville's function A002819(m) = -n.at n=26A002053
- Number of n-node trees with a forbidden limb of length 3.at n=13A002989
- Numbers that are the sum of 8 positive 5th powers.at n=23A003353
- Length of n-th term in Look and Say sequences A005150 and A007651.at n=22A005341
- Number of points on surface of octahedron; also coordination sequence for cubic lattice: a(0) = 1; for n > 0, a(n) = 4n^2 + 2.at n=13A005899
- Inverse Moebius transform applied twice to squares.at n=24A007433
- Impractical numbers: even abundant numbers (A173490) that are not practical(2) (A007620).at n=35A007621
- Coordination sequence T1 for Zeolite Code AFG.at n=18A008012
- Coordination sequence T2 for Zeolite Code EAB and OFF.at n=19A008083
- Coordination sequence T3 for Zeolite Code LIO.at n=18A008131
- Coordination sequence T1 for Zeolite Code LOS.at n=18A008132
- Coordination sequence T4 for Zeolite Code MEI.at n=19A008149
- Coordination sequence T4 for Zeolite Code MFS.at n=16A008176
- Coordination sequence T1 for Zeolite Code TON.at n=16A008241
- Coordination sequence T4 for Zeolite Code TON.at n=16A008244
- Number of distinct orders of permutations of n objects; number of nonisomorphic cyclic subgroups of symmetric group S_n.at n=44A009490
- a(0) = 1, a(n) = n^2 + 2 for n > 0.at n=26A010000
- a(n) = floor( n*(n-1)*(n-2)/23 ).at n=26A011905
- Molien series of 4-dimensional representation of u.g.g.r. #8.at n=11A013978