15817
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
- 2
- Divisor Sum
- 15818
- 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
- 15816
- Möbius Function
- -1
- Radical
- 15817
- 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
- 1846
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers that are the sum of 4 positive 6th powers.at n=37A003360
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 11.at n=16A031599
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 72 ones.at n=24A031840
- Primes p from A031924 such that A052180(primepi(p)) = 13.at n=24A052233
- Number of unlabeled 4-trees on n vertices.at n=12A078793
- Number of bridged bicyclic skeletons with n carbon atoms (see Parks et al. for precise definition).at n=10A121328
- Indices where A138554 requires only squares < floor(sqrt(n))^2.at n=40A138555
- Primes of the form 210k + 67.at n=38A140855
- Primes congruent to 25 mod 47.at n=36A142376
- Primes congruent to 23 mod 53.at n=33A142553
- Primes congruent to 5 mod 59.at n=35A142732
- Primes congruent to 18 mod 61.at n=29A142816
- Primes p of the form 4*k+1 for which s=26 is the least positive integer such that s*p-(floor(sqrt(s*p)))^2 is a square.at n=15A145050
- Primes in A154935.at n=37A154936
- Number of compositions of n with no part greater than 3 such that no two adjacent parts are equal.at n=28A155822
- Primes p0 such that p0+p1+p2-+2 are primes; p0,p1,p2 are three consecutive primes.at n=14A158351
- Primes expressed as the sum of square of digits of all primes.at n=22A181508
- First of a run of 4 or more consecutive primes which all equal 1 (mod 3).at n=26A185942
- Smallest m such that the period of the continued fraction of sqrt(m) is A215485(n); records of A013646.at n=23A215508
- 50k^2-20k-23 interleaved with 50k^2+30k+17 for k=>0.at n=36A217894