12647
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12648
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12646
- Möbius Function
- -1
- Radical
- 12647
- 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
- 94
- 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
- 1511
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Absolute value of Glaisher's alpha(n).at n=24A002290
- Lists of 4 primes in arithmetic progression; common difference 6.at n=29A033449
- Decimal part of n-th root of a(n) starts with digit 3.at n=34A034080
- Second member of a sexy prime quadruple: value of p+6 such that p, p+6, p+12 and p+18 are all prime.at n=26A046122
- Second term of balanced prime quartets: p(m)-p(m-1) = p(m+1)-p(m) = p(m+2)-p(m+1).at n=7A054801
- Smaller term of closest safe prime pairs.at n=14A059323
- a(0) = 2; a(n) for n > 0 is the smallest prime greater than a(n-1) that differs from a(n-1) by a square.at n=41A073609
- Safe primes (A005385) (p and (p-1)/2 are primes) such that 6*p+1 is also prime.at n=39A075705
- a(n) = Sum_{d|n} (n/d)^(d-1).at n=27A087909
- a(1)=433640083; a(n+1)= the largest prime factor of a(n)+b(n)+c(n), where a(n)<b(n)<c(n) and a(n),b(n) and c(n) are three consecutive primes.at n=21A117631
- Father primes of order 8.at n=25A136077
- Primes of the form 210k + 47.at n=32A140850
- Primes congruent to 30 mod 37.at n=41A142139
- Primes congruent to 19 mod 41.at n=39A142216
- Primes congruent to 5 mod 43.at n=35A142254
- Primes congruent to 4 mod 47.at n=28A142356
- Primes congruent to 5 mod 49.at n=41A142418
- Primes congruent to 33 mod 53.at n=33A142563
- Primes congruent to 52 mod 55.at n=33A142638
- Primes congruent to 50 mod 57.at n=39A142696