15312
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
- 40
- Divisor Sum
- 44640
- Proper Divisor Sum (Aliquot Sum)
- 29328
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4480
- Möbius Function
- 0
- Radical
- 1914
- 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
- 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
- 58
- 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
- Star of David matchstick numbers: a(n) = 6*n*(3*n+1).at n=29A045946
- Products of members of pairs in A075333.at n=30A075337
- Number of (s(0), s(1), ..., s(n)) such that 0 < s(i) < 6 and |s(i) - s(i-1)| <= 1 for i = 1,2,...,n, s(0) = 2, s(n) = 4.at n=9A094306
- When this sequence is interleaved with its first differences and the resulting sequence is divided into blocks of 10 digits, each block contains 10 distinct digits. Each term is chosen to be the smallest that satisfies this property.at n=11A101246
- Numbers n such that 101101 * 10^n + 1 is prime.at n=17A106745
- a(n) = 3600*n^2 - 6751*n + 3165.at n=2A157824
- Number of (w,x,y,z) with all terms in {0,...,n} such that range{w,x,y,z} is not one of the numbers w,x,y,z.at n=12A212569
- a(n) = smallest k such that n is the n-th largest divisor of k.at n=28A225562
- Sum over all Dyck paths of semilength n of products over all peaks p of y_p^x_p, where x_p and y_p are the coordinates of peak p.at n=4A258177
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 259", based on the 5-celled von Neumann neighborhood.at n=28A271056
- Fill an infinite square array by following a spiral around the origin; in the central cell enter a(0)=1; thereafter, in the n-th cell, enter the sum of the entries of those earlier cells that can be seen from that cell.at n=17A280027
- Least common multiple of 5*n+1 and 5*n-1.at n=35A282285
- Least common multiple of 7*n+1 and 7*n-1.at n=25A282286
- a(n) = 60*2^n - 48 (n>=1).at n=7A304376
- Square array A(n,k) = A326128(A388981(n, k)), read by descending antidiagonals.at n=44A388988