12615
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
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 20904
- Proper Divisor Sum (Aliquot Sum)
- 8289
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6496
- Möbius Function
- 0
- Radical
- 435
- Omega Function (Ω)
- 4
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 63
- 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
- no
- Odd
- yes
Appears in sequences
- Pentagonal pyramidal numbers: a(n) = n^2*(n+1)/2.at n=29A002411
- Odd pentagonal pyramidal numbers.at n=7A015223
- Powers of fifth root of 12 rounded down.at n=19A018147
- Powers of fifth root of 12 rounded to nearest integer.at n=19A018148
- Numbers k such that 297*2^k + 1 is prime.at n=22A053365
- Least k for which the integers Floor(k/m^2) for m=1,2,...,n are distinct.at n=33A054062
- a(n) = n*(94 + 5*n + 25*n^2 - 5*n^3 + n^4)/120.at n=18A057703
- a(n) = n*(13*n^2 - 7)/6.at n=18A062025
- a(n) = 15*n^2.at n=29A064761
- Sum of terms of n-th row of A077583.at n=28A077660
- Sum of terms of n-th row of A077661.at n=28A077663
- Group the natural numbers such that the n-th group sum is divisible by the n-th triangular number: (1), (2, 3, 4), (5, 6, 7), (8, 9, 10, 11, 12), (13, 14, 15, 16, 17), (18, 19, 20, 21, 22, 23, 24), ... Sequence contains the group sum.at n=28A086500
- 33-gonal numbers: n(31n-29)/2.at n=29A098923
- Catalan numbers minus odd-indexed Fibonacci numbers.at n=9A122880
- Partial sums of A100119. Sum of first n of the n-th centered n-gonal numbers.at n=17A130218
- Interlacing n^3/2 and n^2(n + 1)/2.at n=28A130656
- a(n) = (n+1)*(2n+1)^2.at n=14A139757
- Maximum value of k^2 * (n-k).at n=44A190798
- Truncated dodecahedron, and truncated icosahedron with faces of centered polygons.at n=7A193248
- Number of 5-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and first differences in -n..n.at n=12A208996