12720
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 40
- Divisor Sum
- 40176
- Proper Divisor Sum (Aliquot Sum)
- 27456
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3328
- Möbius Function
- 0
- Radical
- 1590
- Omega Function (Ω)
- 7
- Little Omega Function (ω)
- 4
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- yes
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- yes
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 107
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Convolved Fibonacci numbers.at n=7A001875
- a(n) = (n^4 + n^2 + 2*n)/4.at n=15A006528
- Denominator of B_{2n}/(-4n), where B_m are the Bernoulli numbers.at n=26A006863
- a(n) = 2*n*(4*n - 1).at n=40A014635
- Triangle of Gaussian binomial coefficients [ n,k ] for q = 23.at n=11A022187
- Triangle of Gaussian binomial coefficients [ n,k ] for q = 23.at n=13A022187
- Number of sublattices of index n in generic 4-dimensional lattice.at n=22A038991
- Denominators of continued fraction convergents to sqrt(799).at n=7A042541
- a(n) = n^3 + n^2 + n + 1.at n=23A053698
- T(n,m) = (1/m!)*Sum_{i=0..m} stirling1(m,i)*(2^i)*(2^i+1)*...*(2^i+n-1).at n=39A059587
- a(n) = Z(S_m; sigma[1](n), sigma[2](n),..., sigma[m](n)) where Z(S_m; x_1,x_2,...,x_m) is the cycle index of the symmetric group S_m and sigma[k](n) is the sum of k-th powers of divisors of n; m=3.at n=22A068020
- Triangular numbers of the form 10*k.at n=31A069498
- Binomial transform of A073145.at n=12A073498
- a(n) = m, the smallest number such that (m+k)/k is prime for k=1, 2, ..., n.at n=3A074200
- Triangular numbers which are 7-almost primes.at n=6A076581
- Largest number m such that a^n == 1 (mod m) whenever a is coprime to m.at n=51A079612
- Third row of Pascal-(1,6,1) array A081581.at n=23A081591
- Largest integer m such that m divides (sigma_(2n+1)(2k-1)-sigma(2k-1)) for all k>=1.at n=25A081863
- Short leg of primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.at n=36A089547
- Numbers that can be expressed as the difference of the squares of primes in exactly four distinct ways.at n=36A092000