315
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
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 624
- Proper Divisor Sum (Aliquot Sum)
- 309
- 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
- 144
- Möbius Function
- 0
- Radical
- 105
- Omega Function (Ω)
- 4
- 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
- 37
- 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
- no
- Odd
- yes
Names
- German
- dreihundertfünfzehn· ordinal: dreihundertfünfzehnste
- English
- three hundred fifteen· ordinal: three hundred fifteenth
- Spanish
- trescientos quince· ordinal: 315º
- French
- trois cent quinze· ordinal: trois cent quinzième
- Italian
- trecentoquindici· ordinal: 315º
- Latin
- trecenti quindecim· ordinal: 315.
- Portuguese
- trezentos e quinze· ordinal: 315º
Appears in sequences
- Number of n-bead necklaces with beads of 2 colors and primitive period n, when turning over is not allowed but the two colors can be interchanged.at n=13A000048
- Crossing number of complete graph with n nodes.at n=14A000241
- Number of 5-level labeled rooted trees with n leaves.at n=4A000357
- Rencontres numbers: number of permutations of [n] with exactly 3 fixed points.at n=4A000449
- Lerch's function q_2(n) = (2^{phi(t)} - 1)/t where t = 2*n - 1.at n=6A001226
- Numbers that are the sum of 4 cubes in more than 1 way.at n=13A001245
- Number of ways of making change for n cents using coins of 1, 2, 4, 12, 24, 48, 96, 120 cents (based on English coinage of 1939).at n=44A001364
- Number of ways of making change for n cents using coins of 1, 2, 4, 12, 24, 48, 96, 120 cents (based on English coinage of 1939).at n=45A001364
- Expansion of 1/(1-x)^2/(1-x^2)/(1-x^6)/(1-x^12)/(1-x^24)/(1-x^48)/(1-x^60).at n=22A001365
- Coefficients of Legendre polynomials.at n=4A001800
- Coefficients of Legendre polynomials.at n=3A001801
- Numerators in expansion of (1 - x)^(-3/2).at n=4A001803
- Expansion of g.f. x/((1 - x)^2*(1 - x^3)).at n=42A001840
- The coding-theoretic function A(n,4,4).at n=17A001843
- Number of n-bead necklaces with 3 colors.at n=7A001867
- Convolved Fibonacci numbers.at n=4A001874
- Denominator of (2/Pi)*Integral_{0..inf} (sin x / x)^n dx.at n=7A002298
- Numbers x such that x^2 + y^2 = p^2 = A002144(n)^2, x < y.at n=55A002366
- a(n) = floor(n(n+2)(2n+1)/8).at n=10A002717
- Numbers k such that (k^2 + 1)/2 is prime.at n=49A002731