7789
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7790
- 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
- 7788
- Möbius Function
- -1
- Radical
- 7789
- 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
- 83
- 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
- 986
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Eleven iterations of Reverse and Add are needed to reach a palindrome.at n=16A015992
- Primes that remain prime through 3 iterations of function f(x) = 10x + 3.at n=25A023300
- Palindromic primes in base 4.at n=27A029972
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 40 ones.at n=41A031808
- Number of primes < n^3.at n=42A038098
- Next prime after n^5.at n=5A053788
- a(n) = 4*n^2 - 7*n + 4.at n=44A054567
- Primes p such that x^59 = 2 has no solution mod p.at n=17A059312
- a(n) is the smallest prime >= 6^n.at n=5A063766
- Numbers which need eleven 'Reverse and Add' steps to reach a palindrome.at n=15A065216
- Primes in which neighboring digits differ at most by 1.at n=33A068148
- a(1) = 2; a(n) is the smallest prime greater than the sum of all previous terms.at n=12A070218
- Primes on axis of Ulam square spiral (with rows ... / 7 8 9 / 6 1 2 / 5 4 3 / ... ) with origin at (1).at n=39A078784
- Primes whose 10's complement is a triangular number.at n=12A082992
- Gregorian calendar years with Ascension Day in April.at n=31A084427
- Number of primes < prime(n)^3.at n=13A086688
- Numbers n which are prime and which when each digit is incremented by 2 with carries ignored yields another prime p with the same property.at n=42A088786
- Sequence A002313 is the sequence of primes p = a*a + b*b, starting 2,5,13,17,..., members p > 2 have p = 1 mod 4. In analogy to the definition of primorial primes use the primes of sequence A002313 to build the product, written here as cp#353+1 or cp#1609-1. If cp#n+1 or cp#n-1 is prime, then n is in the sequence. Using +1 or -1 to define the type of prime cp#n+-1 we get the sequence 1,1,1,1,-1,1,...at n=5A094249
- a(n) is the least prime following A002281(n) repdigits.at n=4A099661
- Smallest prime equal to the sum of exactly 2n+1 distinct odd primes in at least n ways.at n=29A100697