16525
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 20522
- Proper Divisor Sum (Aliquot Sum)
- 3997
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13200
- Möbius Function
- 0
- Radical
- 3305
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 128
- 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 the continued fraction for sqrt(k) has period 41.at n=32A020380
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+4)/m < s for some integer k.at n=42A024847
- Numerators of continued fraction convergents to sqrt(715).at n=6A042376
- Diagonal in array of n-gonal numbers A081422.at n=24A081438
- Composite numbers k such that binomial(5*k, k) == 5^k (mod k).at n=8A109760
- Records in A118878.at n=6A119903
- Nearest integer to the space diagonal of the smallest (measured by the longest edge) primitive (gcd(a,b,c)=1) Euler bricks (a, b, c, sqrt(a^2 + b^2), sqrt(b^2 + c^2), sqrt(a^2 + c^2) are integers). If the space diagonal is an integer then the Euler brick is called a "perfect cuboid". There are no known perfect cuboids.at n=19A141029
- Index of first occurrence of n in A165633.at n=23A165765
- Numbers k such that (77*10^k - 293)/9 is prime.at n=20A288482
- a(n) is the number of permutations of length n that avoid the pattern 321 and the mesh pattern (12, 285) or the same sequence for the mesh patterns (12, 339), (12, 369), (12, 405).at n=10A289609
- a(n) = Sum_{k=1..n} binomial(floor(n/k)+4,5).at n=15A365439
- Number of integer partitions of n whose semi-sums cover an interval of positive integers.at n=51A367402