15731
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
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15732
- 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
- 15730
- Möbius Function
- -1
- Radical
- 15731
- 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
- 53
- 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
- 1833
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Prime quadruples: numbers k such that k, k+2, k+6, k+8 are all prime.at n=14A007530
- Primes that remain prime through 3 iterations of function f(x) = 9x + 8.at n=36A023298
- Palindromic primes in base 8.at n=40A029976
- Primes that are palindromic in base 11.at n=25A029978
- Initial terms of '4-block' primes as described in A032591.at n=22A032592
- Start of a string of exactly 2 consecutive (but disjoint) pairs of twin primes.at n=33A035790
- Denominators of continued fraction convergents to sqrt(276).at n=13A041519
- Numbers whose base-5 representation contains exactly three 0's and three 1's.at n=18A045172
- a(n) = 1 - (7/6)*n + (2/3)*n^3 + (1/2)*n^4.at n=13A046998
- a(n) is the smallest prime such that the number of primes produced according to rules stipulated in Honaker's A048853 is n.at n=14A050673
- a(n) = p.q in decimal notation where p = prime(n) and q is the smallest prime (A066065(n)) such that the concatenation p.q is a prime.at n=36A066064
- Primes associated with A066042.at n=24A066146
- Successive left concatenation of floor(k/2) beginning with n until we reach 1.at n=14A068657
- Primes in A068657.at n=6A068658
- Primes with all odd digits such that the next three primes also contain all odd digits.at n=11A068831
- Primes arising in A086498: a(n) = (2n)-th partial sum of A086498.at n=40A086499
- Lower twin primes with lower twin prime index.at n=18A088460
- a(n) is the lesser term of the smallest twin prime pair such that if P=(a(n)^2+n)^2+n, then P and P+2 are also twin primes. a(n) is 0 if no such pair exists.at n=58A093245
- a(n) = median of the largest prime dividing a random n-digit number.at n=6A124202
- Father primes of order 11.at n=18A136080