12457
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12458
- 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
- 12456
- Möbius Function
- -1
- Radical
- 12457
- 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
- 63
- 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
- 1487
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes that remain prime through 3 iterations of function f(x) = 9x + 8.at n=31A023298
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 68 ones.at n=13A031836
- Primes p such that (p+1)/2 and (p+2)/3 are also primes.at n=28A036570
- Concatenate Fibonacci-lucky numbers.at n=4A039680
- Numerators of continued fraction convergents to sqrt(563).at n=6A042078
- Smallest number m with nonzero digits such that A046810(m)=n.at n=22A046813
- a(n) is the least integer that has exactly n anagrams that are primes.at n=22A046890
- Least prime in A031934 (lesser of 16-twins) whose distance to the next 16-twin is 6*n.at n=13A052357
- Numbers k such that 60*R_k + 1 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=23A056658
- Primes with 10 as smallest positive primitive root.at n=36A061323
- Primes that are a sum of twin primes and their indices.at n=37A088187
- Primes p such that index of p, the sum of p's digits and the number of p's digits are all primes.at n=35A109982
- Primes such that the sum of the predecessor and successor primes is divisible by 31.at n=39A113155
- a(0)=1, a(1)=1, a(n) = 9*a(n/2) for even n >= 2, and a(n) = 8*a((n-1)/2) + a((n+1)/2) for odd n >= 3.at n=25A116526
- Retrograde trajectory of 4 under map k -> A094077(k).at n=52A117150
- a(n) = number of primes <= !n, where !n is subfactorial n.at n=8A126701
- Primes of the form x^2 + 1848*y^2.at n=34A139668
- Primes of the form 210k + 67.at n=31A140855
- Primes congruent to 34 mod 41.at n=39A142231
- Primes congruent to 30 mod 43.at n=37A142279