12318
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 24648
- Proper Divisor Sum (Aliquot Sum)
- 12330
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 4104
- Möbius Function
- -1
- Radical
- 12318
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 156
- Smith Number
- yes
- 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(n) = prime(n)*prime(n-1) + 1.at n=29A023523
- Number of (unordered) ways of making change for n dollars using coins of denominations 1, 5, 10, 25, 50 and 100.at n=3A085502
- Even terms in A118854.at n=4A118855
- a(n) = Sum_{j=0..n} A000293(j).at n=11A143123
- a(n) = 9*n^2 - 3.at n=36A157872
- Number of (n+1) X 4 0..2 arrays with the number of clockwise edge increases in every 2 X 2 subblock unequal to the number of counterclockwise edge increases.at n=3A205818
- Number of (n+1) X 5 0..2 arrays with the number of clockwise edge increases in every 2 X 2 subblock unequal to the number of counterclockwise edge increases.at n=2A205819
- T(n,k) = number of (n+1) X (k+1) 0..2 arrays with the number of clockwise edge increases in every 2 X 2 subblock unequal to the number of counterclockwise edge increases.at n=17A205823
- T(n,k) = number of (n+1) X (k+1) 0..2 arrays with the number of clockwise edge increases in every 2 X 2 subblock unequal to the number of counterclockwise edge increases.at n=18A205823
- Numbers n such that n^2 + 1 is divisible by a 4th power.at n=40A218563
- Number of n X 3 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..1 n X 3 array.at n=22A219699
- Number of nX5 0..1 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.at n=3A281799
- T(n,k)=Number of nXk 0..1 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.at n=31A281802
- Number of 4Xn 0..1 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.at n=4A281805
- Dirichlet self-convolution of the integer partition numbers A000041.at n=30A323764
- Numbers that are both binary Niven numbers and binary Smith numbers.at n=38A334531
- a(0) = 1; a(n) = Sum_{k=1..n} binomial(n,k) * sigma_0(k) * a(n-k).at n=6A340903