6225
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 10416
- Proper Divisor Sum (Aliquot Sum)
- 4191
- 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
- 3280
- Möbius Function
- 0
- Radical
- 1245
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 36
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers k such that 2*3^k + 1 is prime.at n=25A003306
- Number of nonequivalent dissections of an n-gon by nonintersecting diagonals rooted at a cell up to rotation and reflection.at n=7A003456
- Numbers k such that 101^k-100 is prime.at n=9A034926
- Number of binary rooted trees with n nodes and height at most 7.at n=16A036590
- Numbers whose base-5 representation contains exactly two 0's and three 4's.at n=15A045213
- Numbers m such that there are precisely 3 groups of order m.at n=31A055561
- Number of 2 X 2 singular integer matrices with elements from {0,...,n}.at n=28A059306
- For k not divisible by 10, let f(k) be the number obtained by moving the last digit of k to the front. Then a(n) is the smallest k > 0, made of nonzero digits, such that for all 1 <= i < n, i+1 divides f^i(k).at n=7A084392
- Least positive integers, all distinct, that satisfy sum(n>0,1/a(n)^z)=0, where z=(60+I*11)/61.at n=25A084804
- Number of n X n matrices with entries {-1,0,1} that are diagonalizable over the real numbers.at n=2A091502
- Number of compositions (ordered partitions) of n such that some part is repeated consecutively 2 times and no part is repeated consecutively more than 2 times.at n=13A091616
- sigma(n) + n is a square.at n=19A114069
- A106486-encodings of combinatorial games with value 1.at n=27A125992
- Second bisection of A061041: a(n) = A061041(2n+1) = (2*n+1)*(2*n+9).at n=37A145923
- 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, 1, 1), (0, 1, -1), (1, -1, 1), (1, 1, 1)}.at n=7A149736
- Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, 0), (-1, 1), (0, 1), (1, -1), (1, 0)}.at n=8A151451
- Number of (n+1)X(n+1) -8..8 symmetric matrices with every 2X2 subblock having sum zero and one, three or four distinct values.at n=2A211472
- Expansion of (1-3*x+x^2)^2/(1-9*x+28*x^2-35*x^3+15*x^4-x^5).at n=7A216710
- Number of (n+4) X 1 arrays of occupancy after each element moves up to +-4 places including 0.at n=3A222341
- T(n,k)=Number of length (n+k)X1 arrays of occupancy after each element moves up to +-k places including 0.at n=24A222345