68
domain: N
Properties
Digital Properties
- Digit Count
- 2
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 126
- Proper Divisor Sum (Aliquot Sum)
- 58
- 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
- 32
- Möbius Function
- 0
- Radical
- 34
- Omega Function (Ω)
- 3
- 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
- 14
- Smith Number
- no
Classification
- Natural
- yes
- Even
- yes
- Odd
- 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
Names
- German
- achtundsechzig· ordinal: achtundsechzigste
- English
- sixty-eight· ordinal: sixty-eighth
- Spanish
- sesenta y ocho· ordinal: 68º
- French
- soixante-huit· ordinal: soixante-huitième
- Italian
- sessantotto· ordinal: 68º
- Latin
- sexaginta octo· ordinal: 68.
- Portuguese
- sessenta e oito· ordinal: 68º
Appears in sequences
- Mosaic numbers or multiplicative projection of n: if n = Product (p_j^k_j) then a(n) = Product (p_j * k_j).at n=67A000026
- The positive integers. Also called the natural numbers, the whole numbers or the counting numbers, but these terms are ambiguous.at n=67A000027
- Numbers that are not squares (or, the nonsquares).at n=59A000037
- Generalized tangent numbers d(n,1).at n=29A000061
- A Beatty sequence: a(n) = floor(n/(e-2)).at n=48A000062
- Number of transformation groups of order n.at n=66A000113
- Denumerants: Expansion of 1/((1-x)*(1-x^2)*(1-x^5)).at n=33A000115
- Positive zeros of Bessel function of order 0 rounded to nearest integer.at n=21A000134
- a(8i+j) = 13i + a(j), where 1<=j<=8.at n=41A000202
- a(n) = sigma(n), the sum of the divisors of n. Also called sigma_1(n).at n=66A000203
- A Beatty sequence: floor(n*(e-1)).at n=39A000210
- Number of rooted simplicial 3-polytopes with n+3 nodes; or rooted 3-connected triangulations with 2n+2 faces; or rooted 3-connected trivalent maps with 2n+2 vertices.at n=4A000260
- Sums of three squares: numbers of the form x^2 + y^2 + z^2.at n=58A000378
- Numbers where total number of 1-bits in the exponents of their prime factorization is even; a 2-way classification of integers: complement of A000028.at n=35A000379
- Numbers of form x^2 + y^2 + 7z^2.at n=56A000394
- Numbers of form x^2 + y^2 + 2*z^2.at n=63A000401
- Numbers that are the sum of 2 nonzero squares.at n=23A000404
- Numbers that are the sum of three nonzero squares.at n=41A000408
- Numbers that are the sum of 4 nonzero squares.at n=52A000414
- Numbers that are the sum of 2 but no fewer nonzero squares.at n=22A000415