15803
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
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15804
- 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
- 15802
- Möbius Function
- -1
- Radical
- 15803
- 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
- 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
- yes
- Safe Prime
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1844
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Third member of a sexy prime quadruple: value of p+12 such that p, p+6, p+12 and p+18 are all prime.at n=30A046123
- Bessel function Y_0(n) is a monotonically decreasing positive sequence.at n=30A046961
- Primes p such that there is no Carmichael number pqr, p<q<r q, r primes.at n=18A051663
- Third term of balanced prime quartets: p(m-1)-p(m-2) = p(m)-p(m-1) = p(m+1)-p(m).at n=10A054802
- a(n) is smallest safe prime (A005385) such that a(n) + 12*n is the next safe prime, i.e., x = (a(n) - 1)/2 and x + 6*n are closest Sophie Germain primes.at n=27A059327
- Safe primes which are also Sophie Germain primes.at n=38A059455
- Primes of form Sum_{k=1..n} prime(k)^3.at n=1A066525
- Sum of cubes of the first n primes.at n=7A098999
- Primes that are not the sum of 3 hexagonal numbers.at n=70A117089
- Sophie Germain primes for which the reversal is also a Sophie Germain prime.at n=22A118573
- Primes of the form 210k + 53.at n=36A140851
- Primes congruent to 11 mod 47.at n=37A142362
- Primes congruent to 25 mod 49.at n=38A142435
- Primes congruent to 9 mod 53.at n=38A142539
- Primes congruent to 50 mod 59.at n=31A142777
- Primes congruent to 4 mod 61.at n=33A142802
- 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, -1, 1), (0, 1, -1), (1, 0, 1), (1, 1, -1)}.at n=9A148759
- Primes congruent to 35 mod 73.at n=26A154628
- Prime numbers q of primitive Pythagorean triangles such that perimeters are averages of twin prime pairs, p+1=q(prime), a=q^2-p^2, c=q^2+p^2, b=2*p*q, ar=a*b/2; s=a+b+c, s-+1 are primes.at n=27A155187
- Honaker emirps: terms in A033548 that are emirps.at n=23A161118