8458
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12690
- Proper Divisor Sum (Aliquot Sum)
- 4232
- 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
- 4228
- Möbius Function
- 1
- Radical
- 8458
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 83
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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 k such that the continued fraction for sqrt(k) has period 41.at n=17A020380
- Number of primes less than 10^n with initial digit 6.at n=5A073512
- Let 2^k = smallest power of 2 >= binomial(n,[n/2]); a(n) = 2^k - binomial(n,[n/2]).at n=17A094779
- G.f. satisfies A(x) = 1 + x*A(x+x^2).at n=10A127782
- Triangle, read by rows, where T(n,k) = T(n,k-1) + T(n-1,k-2) for n>=k>=2, with T(n+1,1) = T(n+1,0) = T(n,n) and T(0,0) = 1 for n>=0.at n=54A130521
- Triangle, read by rows, where T(n,k) = T(n,k-1) + T(n-1,k-2) for n>=k>=2, with T(n+1,1) = T(n+1,0) = T(n,n) and T(0,0) = 1 for n>=0.at n=55A130521
- Triangle, read by rows, where T(n,k) = T(n,k-1) + T(n-1,k-2) for n>=k>=2, with T(n+1,1) = T(n+1,0) = T(n,n) and T(0,0) = 1 for n>=0.at n=56A130521
- Second edge diagonal of table A176577. (The first edge diagonal is A099627).at n=27A176575
- Q-toothpick sequence (see Comments for precise definition).at n=62A187210
- Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having four, five or six distinct values for every i,j,k<=n.at n=7A211576
- Sum of largest parts of all partitions of n into an odd number of parts.at n=25A222047
- Number of partitions of n in which the largest summand has frequency 1, the next largest summand has frequency at most 2, the third largest has frequency at most 3, etc.at n=37A244395
- Least integer k > 1 such that pi(k)^2 + pi(k*n)^2 is a square, where pi(.) is the prime-counting function given by A000720.at n=2A255677
- Composite numbers n such that Sum_{k = 0..n} (-1)^k * C(n,k) * C(2*n,k) == -1 (mod n^3) (see A234839).at n=15A268303
- Values tilde(B_s(2)) of q-analogs of Fibonacci numbers.at n=11A279007
- a(n) is the sum of the lengths of all the segments used to draw a rectangle of height 2^(n-1) and width n divided into 2^(n-1) rectangles of unit height, in turn, divided into rectangles of unit height and lengths corresponding to the parts of the compositions of n.at n=9A340228
- Numbers k such that the k-th composition in standard order is a concatenation of distinct twins (x,x).at n=27A351009
- Numbers k such that the k-th composition in standard order has even length and alternately equal and unequal parts, i.e., all run-lengths equal to 2.at n=33A351011
- Indices n where a run of primes ends in A376198.at n=10A376752
- Irregular triangle read by rows: T(n,k) is the number of polyominoes of size k, i.e., connected subsets of k square cells (or vertices), of the n X n flat torus, up to cyclic shifts and reflections of rows and columns, as well as interchange of rows and columns; 1 <= k <= n^2.at n=45A385385