6455
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7752
- Proper Divisor Sum (Aliquot Sum)
- 1297
- 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
- 5160
- Möbius Function
- 1
- Radical
- 6455
- 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
- 106
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers n such that prime(n) mod n <= 10.at n=43A022465
- Numbers k such that prime(k) == 3 (mod k).at n=11A023145
- a(0)=2; a(n) is the smallest k > a(n-1) such that the fractional part of k^(1/11) starts with n.at n=22A034076
- Least k such that k-th prime > n * k.at n=9A038606
- Values of pi(x) where x exceeds n * pi(x).at n=9A038624
- a(n) = Sum_{i=0..n} T(i,n-i), array T as in A049735.at n=14A049736
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 4.at n=41A050053
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 24.at n=35A051989
- Index j of prime p(j) such that floor(p(j)/j) = n is first satisfied.at n=9A062742
- Numbers k such that the digits of the k-th prime begin with k.at n=0A067928
- Numbers n such that, as strings, n is a substring of prime(n).at n=1A068575
- "Orderly" Friedman numbers (or "good" or "nice" Friedman numbers): Friedman numbers (A036057) where the construction digits are used in the proper order.at n=13A080035
- Arrange n^2 octagons that each have area 7 so that they leave (n-1)^2 square gaps each with area 2; a(n) is the total area of these polygons.at n=26A086640
- Duplicate of A038606.at n=10A090974
- Number of Dyck paths of semilength n+4, having exactly two long ascents (i.e., ascents of length at least two).at n=6A091135
- Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n, having k long ascents (i.e., ascents of length at least 2). Rows are of length 1,1,2,2,3,3,... .at n=32A091156
- Expansion of g.f. (1 + x + 2*x^2)/((1 - x)^3*(1 - x^3)).at n=29A092498
- Maximal values in A038598.at n=42A093330
- Number of solutions to x*frac[p(x)/x]<=Log[n] or A004648(n)<=Log[n].at n=19A099641
- Triangle read by rows: T(n,k) is the number of noncrossing trees with n edges and k leaves at level 1.at n=59A101371