12421
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12422
- 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
- 12420
- Möbius Function
- -1
- Radical
- 12421
- 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
- 156
- 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
- 1483
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Palindromic primes: prime numbers whose decimal expansion is a palindrome.at n=25A002385
- Centered 12-gonal numbers, or centered dodecagonal numbers: numbers of the form 6*k*(k-1) + 1.at n=45A003154
- Octal palindromes which are also primes.at n=20A006341
- Coordination sequence for sigma-CrFe, Position Xa.at n=28A009962
- Primes that remain prime through 3 iterations of function f(x) = 2x + 9.at n=27A023276
- a(n) = smallest prime == 1 (mod 4) such that a(n) is a square mod a(i), all i<n.at n=8A034700
- Triangle read by rows, related to number of permutations of [n] with 0 successions and k rises.at n=31A046739
- Triangle read by rows, related to number of permutations of [n] with 0 successions and k rises.at n=34A046739
- a(n) = (117*n^2 - 99*n + 2)/2.at n=15A050408
- Palindromic primes containing no pair of consecutive equal digits.at n=22A050784
- a(n) = smallest number > a(n-1) such that a(1)*a(2)*...*a(n) + 1 and a(1)*a(2)*...*a(n) - 1 are primes.at n=32A051956
- Prime number spiral (clockwise, Southwest spoke).at n=19A054568
- Palindromic primes with strictly increasing digits up to the middle and then strictly decreasing.at n=14A062351
- Smallest prime beginning and ending symmetrically with concatenation of first n natural numbers. Need not be a palindrome.at n=1A068137
- Primes formed by the concatenation 1, n, n^2, n, 1.at n=0A068676
- Numbers n such that phi(n) + sigma(n) = n + reversal(n).at n=26A069217
- Smallest prime of the form 1,n,2n,...(k-1)n,kn,(k-1)n,...2n,n,1 for some k.at n=1A069583
- Palindromic primes with digit sum 10.at n=1A070250
- Third diagonal of triangle in A046739.at n=5A070315
- Numbers n of the form k + reverse(k) for exactly three k.at n=27A071914