12278
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
- 21072
- Proper Divisor Sum (Aliquot Sum)
- 8794
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5256
- Möbius Function
- -1
- Radical
- 12278
- 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
- 125
- 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
- yes
- Odd
- no
Appears in sequences
- A Fielder sequence: a(n) = a(n-1) + a(n-2) - a(n-6), n >= 7.at n=21A001635
- Sum of Gaussian binomial coefficients [ n,k ] for q=4.at n=5A006118
- Positive numbers k such that k and 7*k are anagrams in base 9 (written in base 9).at n=1A023084
- Number of irreducible representations of symmetric group S_n for which every matrix has determinant 1.at n=33A045923
- Number of basis partitions of n+25 with Durfee square size 5.at n=32A053800
- Number of 2 X 2 matrices with elements from {0,1,2,...,n} and with Nim-Determinant 1. (The Nim-Determinant of the 2 X 2 matrix [a,b; c,d] is defined to be a*d xor b*c, where * denotes Nim-Multiplication.)at n=37A059954
- a(n) = 343*n - 70.at n=35A157374
- Number of (n+2) X 3 binary arrays with each 3 X 3 subblock singular.at n=2A186044
- Number of (n+2) X 5 binary arrays with each 3 X 3 subblock singular.at n=0A186046
- T(n,k)=Number of (n+2)X(k+2) binary arrays with each 3X3 subblock singular.at n=3A186052
- T(n,k)=Number of (n+2)X(k+2) binary arrays with each 3X3 subblock singular.at n=5A186052
- Number of partitions of n+3 with largest inscribed rectangle having area <= n.at n=31A218624
- Numbers k such that 3^k + 20 is prime.at n=32A219040
- Number of n X 3 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 2 and every value within 2 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.at n=20A253218
- a(n) = 2*(3 + 2 n + 3 n^2 + 3 n^3 + 3 n^4 + n^5 + n^6).at n=4A276351
- Expansion of (2*x*exp(x)-3)/(1-x).at n=7A296944
- Numbers k such that 405*2^k+1 is prime.at n=24A323102
- a(n) is the largest k such that the sum of k consecutive reciprocals 1/p_n + ... + 1/p_(n+k-1) does not exceed 1 (where p_n = n-th prime).at n=19A327600
- a(n) = Sum_{k=1..n} binomial(floor(n/k)+4,5).at n=14A365439