268
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 476
- Proper Divisor Sum (Aliquot Sum)
- 208
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- yes
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 132
- Möbius Function
- 0
- Radical
- 134
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 29
- 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
- zweihundertachtundsechzig· ordinal: zweihundertachtundsechzigste
- English
- two hundred sixty-eight· ordinal: two hundred sixty-eighth
- Spanish
- doscientos sesenta y ocho· ordinal: 268º
- French
- deux cent soixante-huit· ordinal: deux cent soixante-huitième
- Italian
- duecentosessantotto· ordinal: 268º
- Latin
- ducenti sexaginta octo· ordinal: 268.
- Portuguese
- duzentos e sessenta e oito· ordinal: 268º
Appears in sequences
- Numbers that are not the sum of 4 tetrahedral numbers.at n=18A000797
- Numbers that are the sum of 2 successive primes.at n=31A001043
- Number of (unordered) ways of making change for n cents using coins of 2, 5 (two kinds), 10, 20, 50 cents.at n=65A001314
- Primes multiplied by 4.at n=18A001749
- v-pile positions of the 4-Wythoff game with i=1.at n=51A001964
- Numbers congruent to {2, 4, 8, 16} (mod 20).at n=54A002081
- Nearest integer to 4 * Pi * n^3 / 3.at n=4A002101
- Numbers k for which the rank of the elliptic curve y^2 = x^3 + k is 2.at n=40A002155
- Period of decimal expansion of 1/(n-th prime) (0 by convention for the primes 2 and 5).at n=56A002371
- Numbers k such that (k^2 + k + 1)/21 is prime.at n=14A002644
- Numbers m such that 6m-1, 6m+1 are twin primes.at n=49A002822
- The number of partitions of {1..3n} that are invariant under a permutation consisting of n 3-cycles.at n=4A002874
- Sorting numbers: maximal number of comparisons for sorting n elements by list merging.at n=54A003071
- a(n) = A000201(A003234(n)) + n.at n=38A003248
- The number m such that A001950(m) = A003231(A003234(n)).at n=52A003250
- Discriminants of real quadratic fields with unique factorization.at n=57A003656
- a(n) is smallest number which is uniquely of the form a(j) + a(k) with 1 <= j < k < n and a(1) = 1, a(2) = 4.at n=52A003666
- a(n) is smallest number which is uniquely of the form a(j) + a(k) with 1 <= j < k < n and a(1) = 1, a(2) = 5.at n=50A003667
- Sum of digits of Euler numbers.at n=49A004099
- Divisible only by primes congruent to 2 mod 5.at n=45A004616