15887
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15888
- 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
- 15886
- Möbius Function
- -1
- Radical
- 15887
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 146
- 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
- 1851
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Coordination sequence for Ni2In, Position Ni1 and In.at n=38A009941
- Numerators of continued fraction convergents to sqrt(663).at n=6A042274
- Numbers whose base-5 representation contains exactly three 0's and three 2's.at n=11A045187
- List of codewords in binary lexicode with Hamming distance 9 written as decimal numbers.at n=2A075943
- Basis for code in A075943.at n=1A075944
- a(0) = 5; for n > 0, a(n) is the greatest prime factor of PP(a(n-1))*a(n-1)-2 where PP(n) is an abbreviation for PreviousPrime(n).at n=6A082132
- Lesser of twin balanced primes (A090403).at n=9A096694
- Smallest prime a(n) such that concatenation of first n+1 primes starting from a(n), separated by n zeros, is prime.at n=30A102109
- Integers that do not appear in A103502.at n=7A103504
- Primes with digit sum = 29.at n=38A106766
- Integers i such that 9*i = 25 X i, but 17*i is not 49 X i.at n=22A115811
- Prime quartet leaders: largest number of a prime quartet.at n=38A119892
- a(n) is the n-th prime of the form x^2+n.at n=10A128968
- Primes p such that p+2, n*(p+2)+6 and p*(p+2)+8 are also prime.at n=6A130735
- Primes of the form k^2 + 11.at n=10A138362
- Primes congruent to 40 mod 53.at n=36A142570
- Primes congruent to 16 mod 59.at n=29A142743
- Primes congruent to 27 mod 61.at n=29A142825
- Primes p such that continued fraction of (1 + sqrt(p))/2 has period 12 : primes in A146336.at n=17A146357
- 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=28A155187