12611
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12612
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12610
- Möbius Function
- -1
- Radical
- 12611
- 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
- 63
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1506
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = 2*(3^n - 2^n) + 1.at n=8A002783
- a(n) = a(n-1) + a(n-1-(number of odd terms so far)).at n=35A007604
- Palindromic primes in base 8.at n=28A029976
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 52 ones.at n=38A031820
- Multiplicity of highest weight (or singular) vectors associated with character chi_7 of Monster module.at n=45A034395
- The Gould numbers.at n=8A040027
- Base 8 palindromes that start with 3.at n=23A043023
- Same rule as Aitken triangle (A011971) except a(0,0)=0, a(1,0)=1.at n=44A046936
- Same rule as Aitken triangle (A011971) except a(0,0)=0, a(1,0)=1.at n=45A046936
- Starting positions of strings of 3 1's in the decimal expansion of Pi.at n=11A050209
- Numbers n of the form k + reverse(k) for exactly two k.at n=32A072040
- Primes which can be represented as the sum of a number and its reverse.at n=33A072382
- a(n) = Sum_{i=1..n} LookAndSay(i).at n=20A079664
- Primes which are also prime if their base 64 representation is interpreted as a base 10 number.at n=33A090717
- a(n) is the lesser term of the smallest twin prime pair such that if P=(a(n)^2+n)^2+n, then P and P+2 are also twin primes. a(n) is 0 if no such pair exists.at n=48A093245
- Primes prime(k) such that (prime(k-1) + prime(k+1) + prime(k+2))/prime(k) = 3.at n=21A094933
- Numbers k such that k + (largest digit of k)! is a palindromic prime.at n=6A095920
- Primes with digital product = 12.at n=13A107697
- Triangle read by rows. The definition is by diagonals. The r-th diagonal from the right, for r >= 0, is given by b(0) = b(1) = 1; b(n+1) = Sum_{k=0..n} binomial(n+2,k+r)*a(k).at n=53A121207
- Triangle read by rows: T(n,k) is the number of set partitions of {1,2,...,n} in which the size of the last block is k, 1<=k<=n; the blocks are ordered with increasing least elements.at n=36A124496