13757
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 13758
- 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
- 13756
- Möbius Function
- -1
- Radical
- 13757
- 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
- 151
- 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
- 1627
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has period 75.at n=12A020414
- a(n) = a(n-1) + Sum_{k=0..n-4} a(k)*a(n-4-k), a(0) = 1. Generalized Catalan Numbers.at n=19A023426
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 23.at n=20A051964
- Primes at which the difference pattern X24Y (X and Y >= 6) occurs in A001223.at n=29A052163
- Primes arising in A053782.at n=22A053872
- Smallest prime p having n different cycles in decimal expansions of k/p, k=1..p-1.at n=37A054471
- Number of n-node labeled graphs without endpoints.at n=6A059167
- Lesser of twin primes whose average is 6 times a prime.at n=35A060213
- a(1)=a(2)=1, a(n+2)=a(n+1)+a(n)+(-2)^n.at n=15A073845
- "Secondary twin primes": a(n) = A006450(A096477(n)).at n=33A096479
- Indices of prime values of heptanacci-Lucas numbers A104621.at n=36A104622
- a(n)=Floor(n*2^(n/2)).at n=18A128441
- List of strictly non-palindromic twin primes {p, p+2}.at n=10A138329
- Lesser of twin primes such that both twin primes have no bases b, 1 < b < p-1, in which p is a palindrome.at n=5A138348
- Primes congruent to 22 mod 41.at n=39A142219
- Primes congruent to 40 mod 43.at n=36A142289
- Primes congruent to 33 mod 47.at n=37A142384
- Primes congruent to 37 mod 49.at n=38A142445
- Primes congruent to 30 mod 53.at n=32A142560
- Primes congruent to 20 mod 57.at n=39A142677