13187
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 13188
- 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
- 13186
- Möbius Function
- -1
- Radical
- 13187
- 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
- 125
- 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
- 1570
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Fibonacci sequence beginning 1, 21.at n=15A022391
- Molien series for complete weight enumerator of self-dual code over GF(5).at n=38A028344
- Discriminants of imaginary quadratic fields with class number 23 (negated).at n=30A046020
- a(n) is the least odd number of the form p + k^2 with p prime and k > 0 which can be represented in exactly n different ways.at n=37A059400
- Primes p that have exactly three primitive roots that are not primitive roots mod p^2.at n=2A060519
- Least number which may be expressed as the sum of a prime number and a nonzero square in exactly n different ways.at n=36A064283
- Primes for which the four closest primes are smaller.at n=28A075030
- Primes for which the five closest primes are smaller.at n=4A075037
- Smallest prime p(k) such that the number of distinct prime divisors of all composite numbers between p(k) and p(k+1) is n.at n=44A075580
- Duplicate of A075580.at n=44A077132
- Primes p such that (r-p)/log(p) > 3, where r is the next prime after p.at n=36A082888
- Prime mean of 8 horizontal, vertical and main diagonal sums associated with primes in A094454.at n=13A094455
- Indices of primes in sequence defined by A(0) = 97, A(n) = 10*A(n-1) + 17 for n > 0.at n=15A101018
- prime(k) for those k where floor((2*(prime(k+1)-prime(k))*PrimePi(k) mod (8*k))/k) = m with m = 9.at n=14A109563
- Odd winning positions in Fibonacci nim.at n=33A120904
- Primes p such that q-p = 30, where q is the next prime after p.at n=12A124596
- Number of base 23 n-digit numbers with adjacent digits differing by four or less.at n=4A126518
- Prime numbers p such that p^3 - (p+1)^2 and p^3 + (p+1)^2 are both primes.at n=13A137476
- Primes congruent to 29 mod 43.at n=40A142278
- Primes congruent to 27 mod 47.at n=32A142378