16591
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
- 16992
- Proper Divisor Sum (Aliquot Sum)
- 401
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16192
- Möbius Function
- 1
- Radical
- 16591
- 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
- 97
- 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 k such that the period of the continued fraction for sqrt(k) contains exactly 25 ones.at n=7A031793
- Denominators of continued fraction convergents to sqrt(551).at n=6A042055
- Numerators of continued fraction convergents to sqrt(951).at n=7A042840
- Numbers whose base-4 representation contains exactly four 0's and three 3's.at n=16A045084
- Smaller of Smith brothers.at n=11A050219
- Numbers k such that 3*2^k - 5 is prime.at n=37A057912
- Numbers k such that 100k+1, 100k+3, 100k+7, 100k+9 are all primes.at n=27A064687
- Let r, s, t be three permutations of the set { 1, 2, 3, ..., n }; a(n) = minimal value of Sum_{i=1..n} r(i)*s(i)*t(i).at n=21A070735
- Least n such that n consecutive values in A080378 equal 0; i.e., exactly n differences between consecutive primes are divisible by 4.at n=8A080380
- First i such that gcd(prime(i)+1, prime(i+1)+1, ..., prime(i+n)+1) > 2.at n=8A111038
- Sum of all repeated parts of all partitions of n.at n=21A163986
- Semiprimes generated by the polynomial 2 * n^2 + 29.at n=19A241554
- a(n) = Sum_{i=1..n} (prime(i+1)-prime(i))*prime(n+1-i).at n=45A343531
- Composite numbers of the form 2*k^2 + 29.at n=19A352949
- a(n) is the numerator of the probability that the free polyomino with binary code A246521(n+1) appears in a version of the Eden growth model on the square lattice, when n square cells have been added.at n=36A367671
- a(n) is the numerator of the probability that a particular one of the A335573(n+1) fixed polyominoes corresponding to the free polyomino with binary code A246521(n+1) appears in the version of the Eden growth model described in A367671 when n square cells have been added.at n=36A367675
- Integers k such that 511*2^k - 1 is prime.at n=32A387925
- Numbers k such that A003415(k) == A276085(k) (mod 5^5), where A003415 is the arithmetic derivative and A276085 is the primorial base log-function.at n=14A391865