270
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 720
- Proper Divisor Sum (Aliquot Sum)
- 450
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 72
- Möbius Function
- 0
- Radical
- 30
- Omega Function (Ω)
- 5
- 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
- 42
- 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
- yes
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Names
- German
- zweihundertsiebzig· ordinal: zweihundertsiebzigste
- English
- two hundred seventy· ordinal: two hundred seventieth
- Spanish
- doscientos setenta· ordinal: 270º
- French
- deux cent soixante-dix· ordinal: deux cent soixante-dixième
- Italian
- duecentosettanta· ordinal: 270º
- Latin
- ducenti septuaginta· ordinal: 270.
- Portuguese
- duzentos e setenta· ordinal: 270º
Appears in sequences
- Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)Pi*n^(3/2), P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record.at n=16A000092
- Number of n-step spiral self-avoiding walks on hexagonal lattice, where at each step one may continue in same direction or make turn of 2*Pi/3 counterclockwise.at n=16A000511
- Number of monosubstituted alkanes C(n)H(2n+1)-X of the form shown in the Comments lines that are stereoisomers.at n=8A000622
- Number of compositions of n into 3 ordered relatively prime parts.at n=24A000741
- Number of compositions of n into 3 ordered relatively prime parts.at n=27A000741
- Numbers that are divisible by at least three different primes.at n=48A000977
- Number of partitions of n into at most 4 parts.at n=29A001400
- Winning moves in Fibonacci nim.at n=47A001581
- Harmonic or Ore numbers: numbers k such that the harmonic mean of the divisors of k is an integer.at n=4A001599
- Fibonacci entry points: a(n) = smallest m > 0 such that the n-th prime divides Fibonacci(m).at n=57A001602
- Numbers k such that 5*2^k - 1 is prime.at n=14A001770
- v-pile positions of the 4-Wythoff game with i=3.at n=51A001968
- Sum of totient function: a(n) = Sum_{k=1..n} phi(k), cf. A000010.at n=29A002088
- Squares written in base 9.at n=14A002442
- Numbers k such that (k^2 + k + 1)/7 is prime.at n=30A002641
- Numbers m such that 6m-1, 6m+1 are twin primes.at n=50A002822
- Number of restricted solid partitions of n.at n=10A002974
- Number of distinct values taken by 3^3^...^3 (with n 3's and parentheses inserted in all possible ways).at n=8A003018
- For n > 4, a(n) is the least integer > a(n-1) with precisely two representations a(n) = a(i) + a(j), 1 <= i < j < n; and a(n) = n for n=1..4.at n=53A003044
- Problimes (second definition).at n=49A003067