265
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 324
- Proper Divisor Sum (Aliquot Sum)
- 59
- 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
- 208
- Möbius Function
- 1
- Radical
- 265
- Omega Function (Ω)
- 2
- 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
- 122
- Smith Number
- yes
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- no
- Odd
- yes
Names
- German
- zweihundertfünfundsechzig· ordinal: zweihundertfünfundsechzigste
- English
- two hundred sixty-five· ordinal: two hundred sixty-fifth
- Spanish
- doscientos sesenta y cinco· ordinal: 265º
- French
- deux cent soixante-cinq· ordinal: deux cent soixante-cinqième
- Italian
- duecentosessantacinque· ordinal: 265º
- Latin
- ducenti sexaginta quinque· ordinal: 265.
- Portuguese
- duzentos e sessenta e cinco· ordinal: 265º
Appears in sequences
- Subfactorial or rencontres numbers, or derangements: number of permutations of n elements with no fixed points.at n=6A000166
- Numbers m such that Fibonacci(m) ends with m.at n=16A000350
- Number of 3-valent trees (= boron trees or binary trees) with n nodes.at n=13A000672
- Permanent of a certain cyclic n X n (0,1) matrix.at n=6A000804
- Padovan sequence (or Padovan numbers): a(n) = a(n-2) + a(n-3) with a(0) = 1, a(1) = a(2) = 0.at n=26A000931
- a(n) = ceiling(n^2/2).at n=23A000982
- Primes multiplied by 5.at n=15A001750
- a(0) = 1, a(1) = 5, a(n) = 4*a(n-1) - a(n-2).at n=4A001834
- Centered square numbers: a(n) = 2*n*(n+1)+1. Sums of two consecutive squares. Also, consider all Pythagorean triples (X, Y, Z=Y+1) ordered by increasing Z; then sequence gives Z values.at n=11A001844
- v-pile positions of the 4-Wythoff game with i=3.at n=50A001968
- Nearest integer to n^2/8.at n=46A001971
- Numbers k for which the rank of the elliptic curve y^2 = x^3 + k is 2.at n=39A002155
- Related to Bernoulli numbers.at n=4A002316
- Numbers k such that binomial(2*k,k) is divisible by (k+1)^2.at n=23A002503
- Earliest sequence with a(a(n))=5n.at n=54A002518
- a(2*n) = a(2*n-1) + a(2*n-2), a(2*n+1) = 2*a(2*n) + a(2*n-1); a(0) = a(1) = 1.at n=9A002531
- A generalized partition function.at n=8A002601
- A generalized partition function.at n=6A002603
- Numbers k such that (k^2 + k + 1)/3 is prime.at n=37A002640
- Number of rotatable partitions of [n].at n=27A002723