12126
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 25344
- Proper Divisor Sum (Aliquot Sum)
- 13218
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3864
- Möbius Function
- 1
- Radical
- 12126
- 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
- Expansion of Product_{m>=1} (1+q^m)^(-5).at n=20A022600
- Numbers k such that sigma(k) = phi(k+1) + phi(k) + phi(k-1).at n=13A065986
- n is divisible by the sum of all divisors of n which are less than the square root of n (values of n where 1 is the only divisor less than sqrt(n) are excluded as trivial cases.).at n=42A088345
- Numbers n such that for some k and a_1,a_2,...,a_k the concatenation of the a_i is equal to n and their product is equal to pi(n).at n=41A097221
- Positive integers k such that k^20 + 1 is semiprime (A001358).at n=39A105282
- Integers k such that 10^k+57 is a prime number.at n=15A135119
- a(n) = smallest number m such that m^2 and n^2 share no common digits and m^2 and n^2 together use all 10 digits, a(n) = 0 if no such m exists.at n=4A158931
- a(n) = smallest number m such that m^2 and n^2 share no common digits and m^2 and n^2 together use all 10 digits, a(n) = 0 if no such m exists.at n=14A158931
- Numbers whose binary representation traces a non-selfcrossing circuit in the honeycomb lattice when each one of its bits, from the most significant to the least significant, is interpreted as a direction to proceed at each vertex.at n=47A255561
- a(n) = n * Sum_{d|n} binomial(d+4,5)/d.at n=14A343546
- Zumkeller numbers k (A083207) such that the next Zumkeller number is k + 12.at n=33A345704
- Expansion of Sum_{k>=0} k! * x^k * (1 + x)^(k+1).at n=7A346550
- Number of non-condensed integer partitions of n into parts > 1.at n=46A370804