15667
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15668
- 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
- 15666
- Möbius Function
- -1
- Radical
- 15667
- 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
- 58
- 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
- 1828
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Largest prime p==3 (mod 8) such that Q(sqrt(-p)) has class number 2n+1.at n=5A002149
- Palindromic primes in base 8.at n=39A029976
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 68 ones.at n=23A031836
- Largest squarefree number k such that Q(sqrt(-k)) has class number n.at n=10A038552
- Discriminants of imaginary quadratic fields with class number 11 (negated).at n=40A046008
- Obtainable by applying +, * and exponentiation to its own digits.at n=27A046469
- Numbers n such that n and n+4^k are all primes for k=1,2,3.at n=33A049493
- a(n) and a(n)+4^k are primes at least for k=1,2,3,4.at n=13A049494
- a(n) and a(n)+4^k are primes at least for k=1,2,3,4,5.at n=5A049495
- a(n) and a(n)+4^k are primes at least for k=1,2,3,4,5,6.at n=2A049496
- a(n) and a(n)+4^k are primes at least for k=1,2,3,4,5,6,7.at n=2A049497
- a(n) and a(n)+4^k are primes at least for k=1,2,3,4,5,6,7,8.at n=1A049498
- Prime number spiral (clockwise, West spoke).at n=21A054570
- Lesser member p of cousin primes (p, p+4) such that (p+1, p+2, p+3) all have the same number of prime divisors (counted with multiplicity).at n=14A094230
- Prime Friedman numbers.at n=9A112419
- Primes for which the weight as defined in A117078 is 23.at n=35A119504
- Let M be the matrix defined in A111490. Sequence gives the sum of the elements of the submatrices (from the upper left element): M(1,1); M(1,1)+M(1,2)+M(1,2)+M(2,2); M(1,1)+M(1,2)+M(1,3)+M(2,1)+M(2,2)+M(2,3)+M(3,1)+M(3,2)+M(3,3), etc.at n=39A123326
- Beastly fax numbers: numbers containing the fax number of the Beast (667, one more than its regular number) in their decimal expansion.at n=25A138563
- Primes congruent to 15 mod 43.at n=39A142264
- Primes congruent to 16 mod 47.at n=38A142367