12719
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
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 15360
- Proper Divisor Sum (Aliquot Sum)
- 2641
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10296
- Möbius Function
- -1
- Radical
- 12719
- 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
- 81
- 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
- Class numbers of quadratic fields.at n=15A001985
- Lucas-Carmichael numbers: squarefree composite numbers k such that p | k => p+1 | k+1.at n=8A006972
- Coordination sequence for Ni2In, Position Ni1 and In.at n=34A009941
- a(n) = n^3 + n^2 + n.at n=23A027444
- Numbers k > 1 such that k mod ord2(k) is even, where ord2(k) is the order of 2 mod k.at n=20A036260
- If p | n, then p+1 | n+1 for composite n.at n=42A056729
- Numbers k such that A055079(k) = 2^k.at n=30A057838
- Row sums of A095167.at n=22A095170
- a(1) = 3, a(2) = 4. a(n) = (largest composite which occurs earlier in sequence) + (largest prime which occurs earlier in sequence).at n=27A120365
- Triangle read by rows: numbers of isomers of unbranched a-4-catapolydecagons.at n=40A120651
- Numbers k such that k and k^2 use only the digits 1, 2, 6, 7 and 9.at n=12A137015
- Products of three distinct happy primes A035497.at n=15A154717
- a(n) = prime(n)^3 + prime(n)^2 + prime(n).at n=8A181149
- a(n) = 8*n^2 + 14*n + 5.at n=39A181890
- Lucas-Carmichael numbers with 3 prime factors.at n=7A216925
- Number of cyclotomic cosets of 11 mod 10^n.at n=39A220021
- Number of partitions of n such that m(2) > m(3), where m = multiplicity.at n=38A240065
- Number of nonnegative integers with property that their base 7/5 expansion (see A024642) has n digits.at n=24A245423
- Least Lucas-Carmichael number divisible by the n-th prime.at n=20A253597
- a(n) = least Lucas-Carmichael number which is divisible by b(n), where {b(n)} (A255602) is the list of all numbers which could be a divisor of a Lucas-Carmichael number.at n=28A253598