12579
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19200
- Proper Divisor Sum (Aliquot Sum)
- 6621
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7176
- Möbius Function
- -1
- Radical
- 12579
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(1) = 1; then the smallest number such that both the forward and reverse n-th partial concatenation is a prime for n > 1. (Reverse concatenation is taken term-wise and not digit-wise.)at n=38A083992
- Integers k such that nextprime(k^5) - prevprime(k^5) = 4.at n=10A090123
- a(n) = Sum_{k=0..floor(n/5)} C(n-4k,k+1).at n=32A099559
- A version of F. K. Hwang's sequence in {3*k, 3*k+1, 3*k+2}.at n=39A123945
- a(3n) = floor(43*2^n/28) - 1, a(3n+1) = a(3n) + 3*2^(n-3), a(3n+2) = floor(17*2^n/7 - 6/7) for n>=3.at n=39A123946
- Weak Goodstein sequence starting at 11.at n=40A137411
- a(n) = (1/9)*(7*2^n + (-1)^n*(3*n+2)) - (n-1)^2.at n=14A140991
- Numbers k such that k^6 - 2 and k^6 + 2 are both primes.at n=19A154938
- Numbers n such that n^6 + 272 is prime.at n=13A161998
- G.f.: exp( Sum_{n>=1} A174462(n)*x^n/n ) where A174462(n) = Sum_{d|n} C(n,d)^2.at n=10A174461
- Wiener index of the n-web graph.at n=20A180576
- Number of -1..1 arrays x(0..n-1) of n elements with zero sum and no two consecutive declines, no adjacent equal elements, and no element more than one greater than the previous (random base sawtooth pattern).at n=26A200174
- Least number having n orderless representations as p^2 + q^2 + r^2, where p, q, and r are primes.at n=14A214512
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 621", based on the 5-celled von Neumann neighborhood.at n=21A273268
- Sum over all partitions of n of the number of distinct parts i of multiplicity i+1.at n=41A276434
- a(n) is the first positive number that has exactly n anagrams which have 3 prime divisors, counted by multiplicity, or 0 if there is no such number.at n=40A369184