12212
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 22176
- Proper Divisor Sum (Aliquot Sum)
- 9964
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5880
- Möbius Function
- 0
- Radical
- 6106
- Omega Function (Ω)
- 4
- 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
- 156
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Powers of 2 written in base 9.at n=13A001357
- a(n) is formed by concatenating a(n-2) and a(n-1), with a(0) = 1, a(1) = 2.at n=4A008352
- "DHK" (bracelet, identity, unlabeled) transform of 0,1,1,1,...at n=28A032244
- Positive numbers for which the sum of digits equals the product of digits.at n=41A034710
- Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,2,2.at n=4A037551
- k th digit of a(n) = number of different digits within 2 places of k (not including k).at n=10A039987
- Numbers having three 2's in base 10.at n=41A043499
- a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 3.at n=15A049908
- McKay-Thompson series of class 45b for Monster.at n=54A058686
- Coefficients of monic irreducible polynomials over GF(3) listed in lexicographic order.at n=31A058944
- Coefficients of monic primitive irreducible polynomials over GF(3) listed in lexicographic order.at n=14A058949
- Integers m such that (x1*x2*..xk)^(x1+x2+..xk) = (x1+x2+..xk)^(x1*x2*..xk) where x1x2..xk are the digits of m in base 10.at n=44A064158
- Coefficients of irreducible polynomials over GF(3) listed in lexicographic order.at n=34A065020
- Nonprimes whose sum of digits is equal to its product of digits.at n=33A066307
- Frobenius number of the numerical semigroup generated by three consecutive hexagonal numbers.at n=11A069758
- a(n) = prime(n) + prime(n^2).at n=37A092504
- a(n) = (1/n!)*A001565(n).at n=22A094792
- n expressed in Fibonacci binary-like number system using only 1's and 2's.at n=19A108960
- Numbers with digits 1 and 2 and at least one of each.at n=34A111066
- Ternary emirpimes.at n=13A119684