8629
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8630
- 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
- 8628
- Möbius Function
- -1
- Radical
- 8629
- 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
- 1075
- 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 47.at n=16A020386
- a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, |s(i) - s(i-1)| = 1 for i = 1,2; |s(i) - s(i-1)| <= 1 for i >= 3, s(n) = 2. Also a(n) = T(n,n-2), where T is the array defined in A024996.at n=8A026069
- 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 7.at n=25A031420
- Consider all integer triples (i,j,k), j >= k > 0, with binomial(i+2,3)=j^3+k^3, ordered by increasing i; sequence gives k values.at n=19A054207
- n consecutive primes differ by 4 or more starting at a(n), or n consecutive primes with no twin primes.at n=20A054690
- n consecutive primes differ by 4 or more starting at a(n), or n consecutive primes with no twin primes.at n=21A054690
- n consecutive primes differ by 4 or more starting at a(n), or n consecutive primes with no twin primes.at n=19A054690
- n consecutive primes differ by 4 or more starting at a(n), or n consecutive primes with no twin primes.at n=22A054690
- New records in A054690 (start of n consecutive non-twin primes).at n=6A054691
- First member of a prime triple in a 2p-1 progression.at n=39A057326
- Integers n > 1997 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 1997.at n=11A063055
- Primonacci numbers: a(n)=a(n-2)+a(n-3)+a(n-5)+a(n-7)+a(n-11)+...+a(n-p(k))+... until n <= p(k), where p(k) is the k-th prime. a(1)=a(2)=1.at n=25A078465
- Class 7- primes.at n=1A081426
- Primes arising in A085042: a(n) = the n-th partial sum of A085042.at n=23A085043
- Let n range through the odd numbers skipping multiples of 5; a(n) = n-th prime ending in n.at n=11A089779
- Primes p such that the sum of the digits of p is not prime, but the sum of each digit raised to the 4th power is prime.at n=8A091368
- Primes of the form prime(n)*prime(n+1) - 4.at n=10A092761
- Primes that represent some mean of 4 consecutive (2 smaller, itself, 1 larger) primes.at n=23A094932
- a(1)=1. a(n) = a(n-1) + sum of the triangular numbers which are among the first (n-1) terms of the sequence.at n=24A100963
- Number of length-n American English expressions for nonnegative integers (spaces, hyphens, and commas excluded).at n=22A121064