266
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 480
- Proper Divisor Sum (Aliquot Sum)
- 214
- 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
- 108
- Möbius Function
- -1
- Radical
- 266
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 29
- 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
- zweihundertsechsundsechzig· ordinal: zweihundertsechsundsechzigste
- English
- two hundred sixty-six· ordinal: two hundred sixty-sixth
- Spanish
- doscientos sesenta y seis· ordinal: 266º
- French
- deux cent soixante-six· ordinal: deux cent soixante-sixième
- Italian
- duecentosessantasei· ordinal: 266º
- Latin
- ducenti sexaginta sex· ordinal: 266.
- Portuguese
- duzentos e sessenta e seis· ordinal: 266º
Appears in sequences
- Numbers k such that k^4 + 1 is prime.at n=38A000068
- Coefficient of x^5 in expansion of (1 + x + x^2)^n.at n=4A000574
- Number of nonnegative solutions to x^2 + y^2 + z^2 <= n.at n=52A000606
- Number of compositions of n into 4 ordered relatively prime parts.at n=10A000742
- Stirling numbers of the second kind, S(n,6).at n=2A000770
- Number of symmetrical planar partitions of n (planar partitions (A000219) that when regarded as 3-D objects have just one symmetry plane).at n=18A000784
- Genus of complete graph on n nodes.at n=59A000933
- n! never ends in this many 0's.at n=51A000966
- Numbers that are divisible by at least three different primes.at n=47A000977
- Dimensions (sorted, with duplicates removed) of real simple Lie algebras.at n=55A001066
- Moran numbers: k such that k/(sum of digits of k) is prime.at n=25A001101
- 4-dimensional pyramidal numbers: a(n) = (3*n+1)*binomial(n+2, 3)/4. Also Stirling2(n+2, n).at n=6A001296
- Bessel polynomial y_n(x) evaluated at x=1.at n=4A001515
- a(1)=2, a(2)=3; for n >= 3, a(n) is smallest number that is uniquely of the form a(j) + a(k) with 1 <= j < k < n.at n=50A001857
- Numbers dividing A002037(i) and larger than A002037(i-1), for some i>0.at n=22A002038
- Number of partitions of n with exactly two part sizes.at n=39A002133
- a(n) is the number of partitions of 5n that can be obtained by adding together five (not necessarily distinct) partitions of n.at n=4A002222
- Numbers k such that 15*2^k - 1 is prime.at n=19A002237
- Numbers k such that 33*2^k - 1 is prime.at n=17A002240
- a(n) = Sum_{d|n, d <= 3} d^2 + 3*Sum_{d|n, d>3} d.at n=39A002660