8731
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8732
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8730
- Möbius Function
- -1
- Radical
- 8731
- 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
- 127
- 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
- 1088
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Triangular numbers written backwards.at n=52A004158
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 93.at n=8A031591
- Number of partitions of n into parts not of the form 9k, 9k+4 or 9k-4. Also number of partitions with at most 3 parts of size 1 and differences between parts at distance 3 are greater than 1.at n=42A035943
- Discriminants of imaginary quadratic fields with class number 17 (negated).at n=21A046014
- Primes with distinct digits in descending order.at n=42A052014
- Rounded volume of a regular tetrahedron with edge length n.at n=42A071399
- Initial term in sequence of four consecutive primes whose consecutive differences have d-pattern = [6, 4, 6]; short d-string notation for pattern = [646].at n=15A078856
- Primes p such that the differences between the 5 consecutive primes starting with p are (6,4,6,6).at n=3A078964
- Primes in which the unit place digit is 1 and the k-th most significant digit is prime (2,3,5,7) if k is prime else is composite (4,6,8,9,0).at n=20A089704
- Balanced primes of order nine.at n=5A096701
- Primes whose digit reversal is a triangular number.at n=8A115705
- Primes prime(i) such that their sum-of-index-digits A007953(i) and their sum-of-digits A007605(i) are consecutive primes.at n=40A117460
- A106486-encodings of combinatorial games equivalent to game {0|0}.at n=23A125994
- Primes p such that the largest prime factor of p+1 has Erdős-Selfridge class+ < N-1 if p is of class N+.at n=31A129470
- Primes p of Erdos-Selfridge class 4+ with largest prime factor of p+1 not of class 3+.at n=5A129472
- Primes of the form 4x^2+4xy+211y^2.at n=31A139985
- Primes of the form 15x^2+91y^2.at n=31A140022
- Primes of the form 43x^2+2xy+43y^2.at n=31A140041
- Primes congruent to 2 mod 29.at n=37A141978
- Primes congruent to 20 mod 31.at n=34A142024