16651
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
- 2
- Divisor Sum
- 16652
- 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
- 16650
- Möbius Function
- -1
- Radical
- 16651
- 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
- 66
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1926
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Cuban primes: primes which are the difference of two consecutive cubes.at n=33A002407
- Smallest prime beginning a complete Cunningham chain (of the second kind) of length n.at n=6A005603
- Primes that are palindromic in base 5.at n=26A029973
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 66 ones.at n=26A031834
- Primes of the form 666*n + 1.at n=8A037029
- Primes arising in A048969.at n=29A048977
- Primes p whose period of reciprocal equals (p-1)/5.at n=34A056210
- First member of a prime quadruple in a 2p-1 progression.at n=10A057327
- First member of a prime 5-tuple in a 2p-1 progression.at n=3A057328
- First member of a prime sextuplet in a 2p-1 progression.at n=0A057329
- First member of a prime n-tuplet in a 2p-1 progression.at n=5A057330
- First member of a prime n-tuplet in a 2p-1 progression.at n=6A057330
- Smallest prime p such that the infinite sequence {p, p'=2p-1, p''=2p'-1, ...} begins with a string of exactly n primes.at n=6A064812
- a(n) = floor(Pi^n mod n^Pi).at n=23A066434
- Group the natural numbers so that the n-th group contains n numbers whose sum as well as the group product +1 is prime. Sequence contains the primes arising as the sum of the terms of groups.at n=31A092946
- Expansion of (1+x)/((1-x)^2-5x^3).at n=12A097118
- Duplicate of A005603.at n=6A109828
- Smallest prime beginning (through <*2+1> or/and <*2-1>) a complete Cunningham chain (of the first or the second kind) of length n.at n=6A110089
- Smallest prime p such that p divides m^(m+1)+1, where m = (p-2n-1)/(2n).at n=36A123571
- Largest number k such that k^2 divides A007781(6n+1).at n=36A127854