16619
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 16620
- 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
- 16618
- Möbius Function
- -1
- Radical
- 16619
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 40
- 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
- 1922
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Pisot sequence E(6,16), a(n) = floor( a(n-1)^2/a(n-2) + 1/2 ).at n=8A010915
- Smallest integer k such that 2^n is the largest power of two that is contained in 2^k as a proper substring.at n=24A046300
- Primes that yield a different prime when rotated by 180 degrees.at n=38A048890
- Primes p such that p-12, p and p+12 are consecutive primes.at n=11A053072
- Prime arithmetic mean of ten consecutive primes.at n=38A123096
- List of triples of primes with common difference 12.at n=34A128312
- Expansion of x^3*(x-1)*(x+1) / (x^5-2*x^4+x^2-1).at n=46A135990
- Numbers k such that k and k^2 use only the digits 1, 2, 6, 7 and 9.at n=15A137015
- a(n) = a(n-1) + a(n-2) + digsum(a(n-1)) + digsum(a(n-2)), with a(0)=0 and a(1)=1.at n=17A140131
- Primes congruent to 28 mod 47.at n=39A142379
- Primes congruent to 30 mod 53.at n=38A142560
- Primes congruent to 40 mod 59.at n=28A142767
- Primes congruent to 27 mod 61.at n=31A142825
- 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, 0, 1), (-1, 1, 1), (0, 0, 1), (1, 0, -1)}.at n=10A148319
- Primes p such that 6p-7, 6p-5, 6p-1 are all prime.at n=38A157042
- Chen primes A109611(k) which have the same sum-of-digits as their index k.at n=33A176012
- Haros-Farey sequence whose argument is the Fibonacci number; Farey(m) where m = Fibonacci(n + 1).at n=11A176499
- Least prime p such that pi(p*n)^2 + 1 = prime(q*n) for some prime q.at n=11A260219
- Balanced primes of order one ending in 9.at n=2A303095
- Number of integer partitions of n such that every pair of distinct parts has a different quotient.at n=39A325853