2222
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- yes
- Repdigit
- yes
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3672
- Proper Divisor Sum (Aliquot Sum)
- 1450
- 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
- 1000
- Möbius Function
- -1
- Radical
- 2222
- Omega Function (Ω)
- 3
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 32
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- 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
Appears in sequences
- Trajectory of 1 under map x->x + (x-with-digits-reversed).at n=9A001127
- a(n) = 2*(10^n - 1)/9.at n=4A002276
- a(n) = n^2 + prime(n).at n=44A004232
- Numbers that contain only 1's and 2's. Nonempty binary strings of length n in lexicographic order.at n=29A007931
- Coordination sequence for MgZn2, Mg position.at n=12A009939
- Numbers k such that C(k,3) = C(x,3) + C(y,3) is solvable.at n=48A010330
- Repdigit numbers, or numbers whose digits are all equal.at n=29A010785
- Numbers > 9 with all digits the same.at n=19A014181
- Strobogrammatic numbers: numbers that are the same upside down (using calculator-style numerals).at n=50A018846
- Doublets: base-10 representation is the juxtaposition of two identical strings.at n=21A020338
- Numbers k such that the sum of the digits of Fibonacci(k) is k.at n=19A020995
- Number of 1's in n-th term of A007651.at n=29A022466
- Convolution of (F(2), F(3), F(4), ...) and A000201.at n=11A023653
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (composite numbers), t = (F(2), F(3), ...).at n=10A024589
- n written in fractional base 4/2.at n=30A024630
- a(n) = greatest number in row n of A026098 that is not a positive power of 2.at n=44A026104
- a(n) = T(n,0) + T(n,1) + ... + T(n,n), T given by A026519.at n=9A026531
- a(n) = Sum_{j=0..n} T(n, j), where T is given by A026552.at n=9A026564
- Repdigit - 1 is prime.at n=7A028987
- Even palindromes.at n=51A029951