12211
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 7
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12212
- 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
- 12210
- Möbius Function
- -1
- Radical
- 12211
- 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
- 112
- 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
- 1460
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes in ternary.at n=36A001363
- Primes of form k^2 + k + 1.at n=34A002383
- Primes that contain digits 1 and 2 only.at n=5A020450
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 76 ones.at n=6A031844
- Smallest n-digit prime containing only digits 1 or 2 or -1 if no such prime exists.at n=4A036229
- Primes having only {0, 1, 2} as digits.at n=13A036953
- n written efficiently in natural numbers base, i.e., in form ...wxyz where n = 1*z + 2*y + 3*x + 4*w + ... with z <= 1, y < 2, x < 3, w < 4, ...at n=21A055611
- Successive positions in Tower of Hanoi (with three pegs {0,1,2}) where xyz means smallest disk is on peg z, second smallest is on peg y, third smallest on peg x, etc. and leading zeros indicate largest disks are all on peg 0.at n=19A055662
- Discriminants of imaginary quadratic fields with class number 25 (negated).at n=22A056987
- Primes which can be written as (b^k+1)/(b+1) for positive integers b and k.at n=41A059055
- Primes p such that x^37 = 2 has no solution mod p.at n=38A059223
- Numerators of the determinant of matrix (M(n) - H(n)), where H(n) is the n-th Hilbert matrix and M(n) is an n X n matrix with i,j-th entry i+j-1.at n=11A061913
- Primes whose sum of digits is 7.at n=37A062337
- Primes having only {1, 2, 3} as digits.at n=37A062350
- A064637 converted to factorial base.at n=15A064477
- The zero-free, right-to-left factorial walk encoding for each rooted plane tree encoded by A014486. Sequence A071155 shown with factorial expansion (A007623).at n=30A071157
- Factorial expansion of A071156.at n=29A071158
- Numbers n of the form k + reverse(k) for exactly two k.at n=30A072040
- Primes which can be represented as the sum of a number and its reverse.at n=31A072382
- Group the natural numbers such that the n-th group contains n terms and the group sum is the smallest possible prime: (2), (1, 4), (3, 5, 9), (6, 7, 8, 10), (11, 12, 13, 14, 17), (15, 16, 18, 19, 20, 21), ... Sequence gives group sums.at n=28A075345