8389
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
- 2
- Divisor Sum
- 8390
- 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
- 8388
- Möbius Function
- -1
- Radical
- 8389
- 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
- 65
- 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
- 1051
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Juxtapose pairs of primes.at n=11A007795
- a(n) = T(n,n-1), T given by A026552. Also a(n) is the number of integer strings s(0),...,s(n) counted by T, such that s(n)=1.at n=11A026554
- Palindromic primes in base 3.at n=18A029971
- Primes that are concatenations of two consecutive primes.at n=2A030461
- 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 10.at n=9A031423
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 54 ones.at n=20A031822
- Primes that are concatenations of k with k + 6.at n=10A032629
- Number of partitions satisfying (cn(1,5) = cn(4,5) and cn(0,5) <= cn(2,5) and cn(0,5) <= cn(3,5) and cn(1,5) <= cn(2,5) and cn(1,5) <= cn(3,5)).at n=50A036817
- Numerators of continued fraction convergents to sqrt(140).at n=6A041256
- Numbers whose base-7 representation contains exactly four 3's.at n=10A043408
- Concatenate the n-th and (n+1)st prime.at n=22A045533
- Concatenation of 2 or more prime numbers is prime (each term starts where previous term left off).at n=3A045735
- Primes whose sum of digits is the perfect number 28.at n=17A048517
- a(n)=T(n,n+1), array T as in A049735.at n=36A049741
- Number of bracelet structures using exactly six different colored beads.at n=10A056361
- Number of primitive (period n) bracelet structures using exactly six different colored beads.at n=10A056370
- Let prime(i) = i-th prime, let twin(n) = (P,Q) be n-th pair of twin primes; sequence gives prime(Q).at n=37A057473
- Primes such that replacing each digit d with d copies of the digit d produces a prime. Zeros are not allowed.at n=44A057628
- Primes p such that p and p^2 have same digit sum.at n=17A058370
- Triangle T(n,k) giving the number of simple matroids of rank k on n labeled points (n >= 2, 2 <= k <= n).at n=16A058720