12456
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 33930
- Proper Divisor Sum (Aliquot Sum)
- 21474
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4128
- Möbius Function
- 0
- Radical
- 1038
- Omega Function (Ω)
- 6
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 125
- 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
- Numbers k such that 247*2^k+1 is prime.at n=23A032500
- Special values of Hermite polynomials.at n=5A079949
- Triangle read by rows in which the n-th row contains the n numbers in increasing order formed by the concatenation of first n-1 numbers. (The digits of the numbers with 2 or more digits are taken as one entity.) First row is taken to be 0.at n=18A081539
- Numbers k such that 6*R_k + 1 is a prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=27A096507
- a(n) = Sum_{i=1..n, j=1..n, gcd(i,j)=1} (n+1-i)*(n+1-j).at n=15A115004
- Expansion of (1-x)/(1-4*x-6*x^2).at n=6A147518
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 1), (1, 0, 1), (1, 1, -1)}.at n=9A148824
- The number of homogeneous trisubstituted linear alkanes.at n=26A159938
- a(n) = 6*a(n-1)-8*a(n-2) for n > 10; a(0)=221, a(1)=2754, a(2)=12456, a(3)=77697, a(4)=589869, a(5)=5333271, a(6)=48222198, a(7)=218509695, a(8)=3071851356, a(9)=12683673552, a(10)=51137150880.at n=2A177420
- Number of 4-step self-avoiding walks on an n X n square summed over all starting positions.at n=19A188149
- Number of -n..n arrays x(0..2) of 3 elements with zeroth through 2nd differences all nonzero.at n=11A199944
- Subsets of positive integers arranged in canonical order.at n=34A213059
- a(n) = phi( a(n-1) + a(n-2) + 1) with a(0) = 0 and a(1) = 1.at n=24A228807
- Numbers k with the property that p = k^2 - 13 and q = k^2 + 13 are consecutive primes.at n=27A248785
- Concatenation of the numbers from 1 to n but omitting 3.at n=4A262573
- Numbers k such that k+1 is a prime, k+2 is twice a prime, and k+3 is three times a prime.at n=28A278583
- Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 6, 7 or 8 king-move adjacent elements, with upper left element zero.at n=10A316689
- a(n) is the least practical number that is divisible by prime(n).at n=39A322371
- Positions of +4's in A346242.at n=37A354814
- a(n) is the concatenation of the positions of 1-bits in the binary expansion of the Gray code for n, when 1 is the rightmost position; a(0) = 0.at n=45A360287