12122
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
- 16
- Divisor Sum
- 21600
- Proper Divisor Sum (Aliquot Sum)
- 9478
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5040
- Möbius Function
- 1
- Radical
- 12122
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 143
- 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
- Numbers that contain only 1's and 2's. Nonempty binary strings of length n in lexicographic order.at n=41A007931
- Expansion of e.g.f. -log(cos(x) - log(x+1)).at n=8A013467
- Least term in period of continued fraction for sqrt(n) is 10.at n=23A031434
- a(n) = (n - 1)*(n^2 + n - 1).at n=23A033445
- Positive numbers for which the sum of digits equals the product of digits.at n=39A034710
- Numbers k such that k is a substring of its base-3 representation.at n=19A038103
- Numbers having three 2's in base 10.at n=39A043499
- Numbers m such that the factorizations of m..m+4 have the same number of primes (including multiplicities).at n=9A045941
- Sixth column (m=5) of triangle A060098.at n=9A060101
- Bisection of triangle A060098: odd-indexed members of column sequences of A060098 (not counting leading zeros).at n=50A060556
- 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=42A064158
- Nonprimes whose sum of digits is equal to its product of digits.at n=31A066307
- The start of a record-breaking run of consecutive integers with a number of prime factors (counted with multiplicity) equal to 4.at n=4A067814
- Numbers in base -3.at n=32A073785
- Smallest index i such that next_prime( 2*prime(i) ) - 2*prime(i) = 2n - 1.at n=32A074973
- A Wallis pair (x,y) satisfies sigma(x^2) = sigma(y^2); sequence gives x's for indecomposable Wallis pairs with x < y (ordered by values of x).at n=27A075768
- Numbers n such that n*359# +-1 are twin primes, where 359# = 72nd primorial (A002110(72)).at n=14A087907
- Convoluted convolved Fibonacci numbers G_6^(r).at n=27A089111
- Output of the linear congruential pseudo-random number generator used in function rand() as described in Kernighan and Ritchie, when seeded with 0.at n=8A096554
- List of Lyndon words on {1,2} sorted first by length and then lexicographically.at n=12A102659