7786
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 12420
- Proper Divisor Sum (Aliquot Sum)
- 4634
- 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
- 3648
- Möbius Function
- -1
- Radical
- 7786
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 101
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Magic numbers: atoms with full shells containing any of these numbers of electrons are considered electronically stable.at n=33A018227
- Number of partitions of 1/n into 4 reciprocals of positive integers.at n=16A020327
- Base-9 palindromes that start with 1.at n=35A043028
- Numbers having four 1's in base 9.at n=23A043460
- Composite n such that the sums of the composite numbers up to n, +/- 1, are twin primes.at n=42A065022
- a(0)=1, a(n) is the smallest integer > a(n-1) such that the largest element in the simple continued fraction for S(n)= 1/a(0)+1/a(1)+1/a(2)+...+1/a(n) equals 2n.at n=44A070898
- Consider the array T(n, m) where the n-th row is the sequence of integer coefficients of A(x), where 1<=a(n)<=n, such that A(x)^(1/n) consists entirely of integer coefficients and where m is the (m+1)-th coefficient. This is the row sum of A to the first coefficient of one.at n=38A112285
- x-values in the solution to x^2 - 20*y^2 = 176.at n=14A228207
- Numbers k such that k, k+1, k+2, and k+3 are not divisible by any of their nonzero digits.at n=36A244358
- Numbers n such that n, n+1, n+2, n+3, and n+4 are not divisible by any of their nonzero digits.at n=2A244359
- Number of primes between the n-th and (n+1)-st Carmichael numbers.at n=34A256520
- G.f.: Product_{m>0} 1/(1 + x^m + 2*x^(2*m) + 3*x^(3*m)).at n=21A290395
- Numbers k such that (13*10^k + 311)/9 is prime.at n=14A295031
- Number of weakly unimodal compositions of n in which the greatest part occurs exactly nine times.at n=59A320320
- Numbers k such that k and k + 1 are both binary Smith numbers (A278909).at n=31A331464
- Even numbers k such that A103230(k) is a perfect square.at n=18A332531
- Lexicographically earliest sequence of distinct terms > 0 such that the terms' cumulative sum and the sequence itself have the same digit succession.at n=64A332803
- a(n) is the number of vertices formed by n-secting the angles of a nonagon (enneagon).at n=27A335782
- Numbers k with a Goldbach partition (p,q) such that k | (p*q - 1).at n=45A336582
- a(n) = A337339(n) - n.at n=26A337341