16127
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 16128
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16126
- Möbius Function
- -1
- Radical
- 16127
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 190
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1877
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Greatest prime divisor of prime(n)*prime(n-1) + 1.at n=54A023525
- Least odd prime divisor of p(n)*p(n-1) + 1, or 1 if p(n)*p(n-1) + 1 is a power of 2.at n=54A023527
- Primes of the form k^2 - 2.at n=31A028871
- Numbers whose set of base-11 digits is {1,3}.at n=32A032918
- Numerators of continued fraction convergents to sqrt(645).at n=5A042238
- a(n) = prime(n)^2 - 2.at n=30A049001
- Primes of form p^2 - 2, where p is prime.at n=15A049002
- Primes p of form q^k-2 where q is also a prime and k > 1.at n=21A053705
- Largest prime below prime(n)^2 (A001248).at n=30A054270
- Frobenius number of the numerical semigroup generated by consecutive centered square numbers.at n=6A069760
- Primes of the form 4^k - 2^(k+1) - 1.at n=4A091516
- a(n) = (2^n-1)^2 - 2.at n=6A093112
- Primes that are 2 less than a perfect power m^k, k >= 2.at n=34A094786
- Primes with a single 0 bit in their binary expansion.at n=28A095078
- Primes of the form m^k-k, with m and k > 1.at n=42A099228
- a(n) = 1 + sum{p=primes<n, p does not divide n} a(p).at n=45A112479
- 2*JacobiSymbol(p,5) mod p^2 for p=prime(n).at n=30A113651
- a(n) = 2*a(n-1) - a(n-2) + n + 1.at n=44A121968
- a(1)=1; for n>=2, a(n) = the largest prime dividing n*a(n-1) + 1.at n=31A134487
- Primes congruent to 6 mod 47.at n=40A142357