312
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 6
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 840
- Proper Divisor Sum (Aliquot Sum)
- 528
- 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
- 96
- Möbius Function
- 0
- Radical
- 78
- 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
- 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
- yes
- Odd
- no
Names
- German
- dreihundertzwölf· ordinal: dreihundertzwölfste
- English
- three hundred twelve· ordinal: three hundred twelfth
- Spanish
- trescientos doce· ordinal: 312º
- French
- trois cent douze· ordinal: trois cent douzième
- Italian
- trecentododici· ordinal: 312º
- Latin
- trecenti duodecim· ordinal: 312.
- Portuguese
- trezentos e doze· ordinal: 312º
Appears in sequences
- Numbers k such that k^4 + 1 is prime.at n=44A000068
- Number of ways of writing n as a sum of 4 squares; also theta series of four-dimensional cubic lattice Z^4.at n=36A000118
- Number of ways of writing n as a sum of 4 squares; also theta series of four-dimensional cubic lattice Z^4.at n=18A000118
- Number of ways of writing n as a sum of 6 squares.at n=5A000141
- a(n) = 2*a(n-1) - a(n-2) + a(n-3) + 2^(n-1).at n=7A000253
- Number of paraffins C_n H_{2n-1} X_3 with n carbon atoms.at n=7A000641
- Expansion of Product_{k>=0} (1 + x^(2k+1)); number of partitions of n into distinct odd parts; number of self-conjugate partitions; number of symmetric Ferrers graphs with n nodes.at n=66A000700
- a(n) = 2*(a(n-1) + (n-1)*a(n-2)) for n >= 2 with a(0) = 1.at n=5A000898
- Euler's "numerus idoneus" (or "numeri idonei", or idoneal, or suitable, or convenient numbers).at n=52A000926
- Numbers k such that sum of squares of k consecutive integers >= 1 is a square.at n=35A001032
- Concatenations of cyclic permutations of initial positive integers.at n=5A001292
- Total height of rooted trees with n labeled nodes.at n=3A001864
- Expansion of 1/((1-x)^2*(1-x^4)) = 1/( (1+x)*(1+x^2)*(1-x)^3 ).at n=47A001972
- Class numbers of quadratic fields.at n=18A002141
- Class numbers of quadratic fields.at n=17A002141
- Class numbers of quadratic fields.at n=19A002141
- Absolute value of Glaisher's beta'(2n+1).at n=15A002291
- Numbers y such that p^2 = x^2 + y^2, 0 < x < y, p = A002144(n).at n=29A002365
- Let p = A007645(n) be the n-th generalized cuban prime and write p^2 = x^2 + 3*y^2 with y > 0; a(n) = y.at n=50A002368
- Period of decimal expansion of 1/(n-th prime) (0 by convention for the primes 2 and 5).at n=64A002371