16537
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17280
- Proper Divisor Sum (Aliquot Sum)
- 743
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15796
- Möbius Function
- 1
- Radical
- 16537
- 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
- 40
- Smith Number
- yes
- 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 whose base-5 representation contains exactly three 1's and three 2's.at n=21A045232
- Larger of Smith brothers.at n=10A050220
- Ratio A095107(n)/A095008(n) rounded down.at n=14A095357
- G.f. satisfies A(x) = 1 + x + x^2*A(x)^4.at n=10A137954
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, -1), (0, 1, 1), (1, 0, 0), (1, 1, -1)}.at n=8A150019
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, -1, 1), (0, 1, 1), (1, 0, 1), (1, 1, 0)}.at n=7A151085
- Products (semiprimes) of two distinct double-safe primes.at n=10A157356
- Centered 12-gonal numbers which are semiprimes, intersection of A003154 and A001358.at n=19A218172
- Numbers n such that there is precisely 1 group of order n, 2 of order n + 1 and 3 of order n + 2.at n=9A296024
- Values m that allow maximum period in the Blum-Blum-Shub x^2 mod m pseudorandom number generator.at n=4A338407
- Numbers k such that 6*k + 1 is a prime that can be written as p*q + 2, with p and q being consecutive primes.at n=13A342564
- Non-Brauer numbers.at n=4A349044
- a(n) = Sum_{k=0..floor(n/3)} binomial(n,k) * binomial(n-2*k,k).at n=13A383522