2011
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 4
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2012
- 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
- 2010
- Möbius Function
- -1
- Radical
- 2011
- 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
- 42
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 305
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- 2^n written in base 5.at n=8A000866
- Primes p of the form 3k+1 such that -sqrt(p) < sum_{x=1..p} cos(2*Pi*x^3/p) < sqrt(p).at n=46A000922
- Primes p such that the multiplicative order of 2 modulo p is (p-1)/5.at n=5A001135
- Squares written in base 5.at n=16A001740
- Duplicate of A000866.at n=8A004644
- Primes p such that 2p-1 is also prime.at n=50A005382
- Coordination sequence T2 for Zeolite Code AFR.at n=34A008020
- Coordination sequence T4 for Zeolite Code MFS.at n=28A008176
- Coordination sequence T1 for Zeolite Code MTW.at n=30A008196
- a(n+3) = 5*a(n+2)-4*a(n+1)+a(n).at n=7A012886
- Values of k at which the period of the continued fraction for sqrt(k) sets a new record.at n=29A013645
- Representation of n in base of Catalan numbers (a classic greedy version).at n=31A014418
- Numbers k such that the continued fraction for sqrt(k) has period 94.at n=0A020433
- Smallest nonempty set S containing prime divisors of 8k+3 for each k in S.at n=50A020617
- Primes that remain prime through 2 iterations of the function f(x) = 2x + 5.at n=30A023243
- Primes that remain prime through 3 iterations of function f(x) = 5x + 6.at n=14A023285
- [ Sum (s(j) - s(i))^2 ], 1 <= i < j <= n, where s(k) = 1 + 1/2 + ... + 1/k.at n=52A025216
- a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026670.at n=4A026984
- Sequence satisfies T^2(a)=a, where T is defined below.at n=33A027593
- Primes p such that digits of p appear in p^2.at n=39A030079