311
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 5
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 312
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 310
- Möbius Function
- -1
- Radical
- 311
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 86
- Smith Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 64
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- dreihundertelf· ordinal: dreihundertelfste
- English
- three hundred eleven· ordinal: three hundred eleventh
- Spanish
- trescientos once· ordinal: 311º
- French
- trois cent onze· ordinal: trois cent onzième
- Italian
- trecentoundici· ordinal: 311º
- Latin
- trecenti undecim· ordinal: 311.
- Portuguese
- trezentos e onze· ordinal: 311º
Appears in sequences
- a(n) = floor(n^(3/2)).at n=46A000093
- a(n) is the least number m such that the n-th prime is the least quadratic nonresidue modulo m.at n=4A000229
- Irregular primes: primes p such that at least one of the numerators of the Bernoulli numbers B_2, B_4, ..., B_{p-3} (A000367) is divisible by p.at n=15A000928
- Numbers k such that sum of squares of k consecutive integers >= 1 is a square.at n=34A001032
- Union of all numbers {p, q} where p and q are both primes or powers of primes and q = p+2.at n=54A001092
- Twin primes.at n=37A001097
- Primes == +-1 (mod 8).at n=28A001132
- Lesser of twin primes.at n=19A001359
- Related to Gilbreath conjecture.at n=14A001549
- Squares written in base 5.at n=9A001740
- Numbers k such that phi(k+2) = phi(k) + 2.at n=31A001838
- Cyclic numbers: 10 is a quadratic residue modulo p and class of mantissa is 2.at n=19A001914
- Primes p such that the congruence 2^x == 3 (mod p) is solvable.at n=36A001915
- Primes p such that the congruence 2^x = 5 (mod p) is solvable.at n=34A001916
- Erroneous version of A045535.at n=3A001984
- Class numbers associated with terms of A001986.at n=16A001987
- Prime determinants of forms with class number 2.at n=31A002052
- Number of partitions of n with exactly two part sizes.at n=48A002133
- Primes of the form 4*k + 3.at n=33A002145
- Smallest prime == 7 (mod 8) where Q(sqrt(-p)) has class number 2n+1.at n=9A002146