12315
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
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19728
- Proper Divisor Sum (Aliquot Sum)
- 7413
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6560
- Möbius Function
- -1
- Radical
- 12315
- 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
- 94
- 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
- a(n) = Sum_{k=0..floor(n/2)} T(n-k,k), T given by A026725.at n=19A026735
- a(1) = 3, a(n) = a(n-1) + 4*(a(n-1)-floor(a(n-1)^(1/3))^3).at n=18A096297
- Product of successive primes minus 2.at n=28A124669
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 0), (0, -1, 0), (0, 1, -1), (0, 1, 0), (1, 1, 1)}.at n=7A150840
- Smallest number m such that exactly n odd numbers can be seen as proper subsequences of m in decimal representation.at n=26A164766
- Triangle read by rows:s(n,m)=Sum[StirlingS2[n, k]*StirlingS1[n - k, m]* Binomial[n, k]*(-1)^(m - k), {k, 0, n}];t[n,m]=s[n,m]+s[n,n-m].at n=23A174555
- Triangle read by rows:s(n,m)=Sum[StirlingS2[n, k]*StirlingS1[n - k, m]* Binomial[n, k]*(-1)^(m - k), {k, 0, n}];t[n,m]=s[n,m]+s[n,n-m].at n=25A174555
- Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having one, two, three, four or five distinct values for every i,j,k<=n.at n=7A211572
- Numbers n such that n!!-8 is prime.at n=23A259359
- Partial sums of A299037.at n=46A299767
- a(n) is the maximum value of the quartet index of a bifurcating rooted tree with n leaves.at n=29A300445
- Indices k such that A358128(k) is a square.at n=39A358130
- Number of degree 4 number fields unramified outside the first n prime numbers.at n=4A368057
- Number of integer compositions of n whose maximal runs R all satisfy length(R) < first(R).at n=24A389512