217
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 256
- Proper Divisor Sum (Aliquot Sum)
- 39
- 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
- 180
- Möbius Function
- 1
- Radical
- 217
- 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
- 26
- Smith Number
- no
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
- zweihundertsiebzehn· ordinal: zweihundertsiebzehnste
- English
- two hundred seventeen· ordinal: two hundred seventeenth
- Spanish
- doscientos diecisiete· ordinal: 217º
- French
- deux cent dix-sept· ordinal: deux cent dix-septième
- Italian
- duecentodiciassette· ordinal: 217º
- Latin
- ducenti septendecim· ordinal: 217.
- Portuguese
- duzentos e dezessete· ordinal: 217º
Appears in sequences
- Number of partitions of n, with three kinds of 1,2,3 and 4 and two kinds of 5,6,7,...at n=6A000711
- Expansion of Product_{n>=1} (1 - x^n)^7.at n=40A000730
- Numbers that are not the sum of 4 tetrahedral numbers.at n=12A000797
- From a self-replicating tiling.at n=64A000876
- Number of twin prime pairs < square of n-th prime.at n=26A000885
- Number of free planar polyenoids with n nodes and symmetry point group C_{2v}.at n=14A000936
- n! never ends in this many 0's.at n=42A000966
- Number of sublattices of index n in generic 3-dimensional lattice.at n=9A001001
- Numbers m such that Sum_{k=0..m-1} exp(2*Pi*i*k^3/m) != 0.at n=57A001074
- a(n) = n^3 + 1.at n=7A001093
- Numbers that are the sum of 4 cubes in more than 1 way.at n=4A001245
- Number of ways of making change for n cents using coins of 1, 2, 5, 10, 25 cents.at n=40A001301
- Number of ways of making change for n cents using coins of 1, 2, 5, 10, 25, 50 cents.at n=40A001302
- a(n) is the number of partitions of n into at most 3 parts; also partitions of n+3 in which the greatest part is 3; also number of unlabeled multigraphs with 3 nodes and n edges.at n=48A001399
- Partial sums of A001462; also a(n) is the last occurrence of n in A001462.at n=32A001463
- v-pile counts for the 4-Wythoff game with i=2.at n=41A001966
- Expansion of e.g.f. exp(sin(x)).at n=8A002017
- Numbers k for which the rank of the elliptic curve y^2 = x^3 + k is 2.at n=29A002155
- Odd squarefree numbers with an even number of prime factors that have no prime factors greater than 31.at n=27A002557
- a(n) = Sum_{d|n, d <= 4} d^2 + 4*Sum_{d|n, d>4} d.at n=27A002791