12257
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14976
- Proper Divisor Sum (Aliquot Sum)
- 2719
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9792
- Möbius Function
- -1
- Radical
- 12257
- Omega Function (Ω)
- 3
- 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
- 94
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = 10*n^2 + 7.at n=35A061722
- a(n) = n*(5*n^2 - 3)/2.at n=17A063522
- Number of 5-colorable (i.e., chromatic number <= 5) simple graphs on n nodes.at n=7A076317
- A014486-indices of A083932-trees.at n=23A083934
- Numbers k such that (k / sum of digits of k) and (k+1 / sum of digits of k+1) are both semiprime.at n=21A085774
- Self-convolution of A086582; the first 2^n terms of this sequence gives the 2^n terms that follow the 2^n-th term of A086582.at n=48A086583
- Half-sum (or average) of cubes of two distinct odd primes.at n=29A138855
- Numbers k for which (6+k!)/6 is prime.at n=24A139063
- Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+103)^2 = y^2.at n=9A157119
- A bisection of A063522.at n=8A160674
- Number of (n+3) X 9 binary arrays with every 4 X 4 subblock commuting with each horizontal and vertical neighbor 4 X 4 subblock.at n=8A188102
- Number of strict partitions of 2n + 1 having 1 more even part than odd, so that there is at least one ordering of the parts in which the even and odd parts alternate, and the first and last terms are even.at n=39A239873
- Number of partitions p = [x(1), ..., x(k)], where x(1) >= x(2) >= ... >= x(k), of n such that max(x(i) - x(i-1)) <= number of parts of p.at n=35A241829
- Number of ascent sequences of length n with the maximal number of descents.at n=42A241881
- Number of partitions of n the largest part of which, call it m, appears once, m-1 appears at most twice, m-2 appears at most thrice, etc.at n=36A244393
- The 360 degree spoke (or ray) of a hexagonal spiral of Ulam.at n=32A244803
- Number of partitions of n with product of multiplicities of parts equal to 4.at n=51A266687
- Expansion of 1/(1 - Sum_{k>=2} floor(1/omega(2*k-1))*x^(2*k-1)), where omega() is the number of distinct prime factors (A001221).at n=40A280200
- Expansion of Product_{k>=1} ((1 + x^(5*k)) / (1 - x^k))^k.at n=16A285461
- a(n) = 192*2^n - 31 (n>=1).at n=5A304385