7727
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7728
- 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
- 7726
- Möbius Function
- -1
- Radical
- 7727
- 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
- 88
- 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
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 981
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = floor(n*phi^12), where phi is the golden ratio, A001622.at n=24A004927
- Primes that contain digits 2 and 7 only.at n=6A020459
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 87.at n=17A031585
- Numbers having three 7's in base 10.at n=16A043519
- Primes with multiplicative persistence value 5.at n=19A046505
- Least prime in A031932 (lesser of 14-twins) whose distance to the next 14-twin is 6*n.at n=18A052356
- First term of strong prime quintets: p(m+1)-p(m) > p(m+2)-p(m+1) > p(m+3)-p(m+2) > p(m+4)-p(m+3).at n=20A054808
- Primes with every digit a prime and the sum of the digits a prime.at n=35A062088
- Primes starting and ending with 7.at n=27A062334
- Numbers k such that 10*k-1, 10*k-3, 10*k-7 and 10*k-9 are all prime.at n=30A064975
- Primes p such that (p-1)/2 and (p-3)/4 are also prime.at n=19A066179
- Primes with only prime digits and whose initial, all intermediate and final iterated sums of digits are primes.at n=11A070029
- a(1) =2, a(2) = 3, a(n+2) = smallest prime such that a(n+2) - a(n+1) is a multiple of a(n).at n=8A073680
- Larger of a pair of consecutive primes having only prime digits.at n=10A082756
- Least positive integer that can be represented as the sum of a prime and a triangular number in exactly n ways.at n=45A101182
- Primes of the form 16*k-1 such that 4*k-1 and 8*k-1 are also primes.at n=9A101793
- Primes by index in A001945.at n=47A104499
- Near-repdigit primes with 7 as repeated digit.at n=16A105977
- Primes p such that little googol - p is prime.at n=22A108256
- Numbers k such that the first 9 decimal digits of the k-th Fibonacci number is 1-9 pandigital.at n=3A112516