7757
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7758
- 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
- 7756
- Möbius Function
- -1
- Radical
- 7757
- 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
- 52
- 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
- 984
- 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 13.at n=40A020352
- Primes that contain digits 5 and 7 only.at n=7A020467
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 9.at n=16A031422
- Numbers having four 5's in base 6.at n=17A043392
- Numbers having three 7's in base 10.at n=19A043519
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 19.at n=23A050968
- Fourth term of strong prime quintets: p(m-2)-p(m-3) > p(m-1)-p(m-2) > p(m)-p(m-1) > p(m+1)-p(m).at n=20A054811
- Primes starting and ending with 7.at n=28A062334
- Numbers k such that sigma(k+2) - sigma(k) = prime(k+1) - prime(k).at n=24A067062
- Largest n-digit prime with only prime digits.at n=3A071060
- a(1) = 8; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=45A074344
- Primes which are sandwiched between two numbers having the same unordered canonical form.at n=24A074460
- a(n) = A077708(n+1)/A077708(n).at n=15A077709
- Operation count to create all permutations of n distinct elements using the "streamlined" version of Algorithm L (lexicographic permutation generation) from Knuth's The Art of Computer Programming, Vol. 4, chapter 7.2.1.2. Sequence gives total executions of step L3.1'.at n=5A079753
- Larger of a pair of consecutive primes having only prime digits.at n=11A082756
- Primes having only {3, 5, 7} as digits.at n=27A087363
- Twin primes whose digits are primes.at n=7A087367
- a(n) = r-th prime of the form (p-q)/(q-r) with r=prime(n+1), q=prime(n+2), and primes p > q.at n=40A089577
- Primes which are also prime if their base 31 representation is interpreted as a base 10 number.at n=38A090715
- Numbers m such that the numerator of Sum_{i=1..m} (i-1)/i is prime.at n=55A091815