7925
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 9858
- Proper Divisor Sum (Aliquot Sum)
- 1933
- 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
- 6320
- Möbius Function
- 0
- Radical
- 1585
- Omega Function (Ω)
- 3
- 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
- 101
- 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
- Consider a 2-D cellular automaton generated by the Schrandt-Ulam rule of A170896, but confined to a semi-infinite strip of width n, starting with one ON cell at the top left corner; a(n) is the period of the resulting structure.at n=43A006447
- Smallest positive number that can be written as sum of distinct Fibonacci numbers in n ways.at n=80A013583
- Number of squares on infinite chessboard at <= n knight's moves from a fixed square.at n=24A018836
- Cycle class sequence c(2n) (the number of true cycles of length 2n in which a certain node is included) for zeolite AFO = AlPO4-41 [Al20P20O80] starting with a T2 atom.at n=5A018958
- Numerators of continued fraction convergents to sqrt(637).at n=6A042222
- Numerators of continued fraction convergents to sqrt(881).at n=5A042702
- Integers k such that phi(prime(k)+1) = phi(prime(k)-1).at n=10A066902
- Number of nonisomorphic unrooted unicursal planar maps with n edges (unicursal means that exactly two vertices are of odd valency; there is an Eulerian path).at n=6A069724
- a(n) = 4*(n+1)*n + 5.at n=44A078370
- Number of noncongruent integer-sided 4-dimensional simplices with largest side n.at n=5A097126
- Numbers k such that 2*R_k + 7 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=9A099410
- Number of toothpicks after n stages of 3-D toothpick structure defined in Comments.at n=23A170876
- Riordan array (f(x), x*f(x)) where f(x) is the g.f. of A126931.at n=29A171509
- Numbers k such that Sum_(i=1..k) prime(i)*(-1)^(i+1) is a square.at n=15A175117
- Composite numbers of form 8n+5 with all prime factors of form 8m+5.at n=32A175486
- "Early bird" squares: write the square numbers in a string 149162536496481100... . Sequence gives numbers k such that k^2 occurs in the string ahead of its natural place.at n=32A181585
- Monotonic ordering of set S generated by these rules: if x and y are in S then x^2 + y^2 is in S, and 1 is in S.at n=44A192476
- Number of 1X4 integer matrices with each row summing to zero, row elements in nondecreasing order, rows in lexicographically nondecreasing order, and the sum of squares of the elements <= 2*n^2 (number of collections of 1 zero-sum 4-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations).at n=32A192691
- Numbers of the form (4k+3)^2-8 or (4k+5)^2+4.at n=43A214405
- Number of 2 X n arrays of the minimum value of corresponding elements and their horizontal or diagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 2 X n array.at n=38A220154