12115
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14544
- Proper Divisor Sum (Aliquot Sum)
- 2429
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9688
- Möbius Function
- 1
- Radical
- 12115
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 187
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Iccanobif numbers: add a(n-1) to reversal of a(n-2).at n=18A014260
- Positive numbers for which the sum of digits equals the product of digits.at n=38A034710
- Numerators of continued fraction convergents to sqrt(547).at n=8A042046
- Integers m such that (x1*x2*..xk)^(x1+x2+..xk) = (x1+x2+..xk)^(x1*x2*..xk) where x1x2..xk are the digits of m in base 10.at n=41A064158
- Nonprimes whose sum of digits is equal to its product of digits.at n=30A066307
- Number of different Euler multigraphs with n edges, loops allowed.at n=10A068590
- Numbers k such that (1_100.2_200.3_300 ... 8_800.9_900)*10^k + 1 is prime, i.e., 1 repeated 100 times, concatenated with 2 repeated 200 times, etc.at n=4A108055
- Semiprimes for which both the sum and the product of the digits is also a semiprime.at n=34A118690
- Number of primitive Pythagorean-like triples a^2+b^2=c^2+k for k=3 with 0<c<=10^n.at n=4A121086
- Numbers which are the sum of 3 cubes of distinct odd primes.at n=32A138853
- Number of binary strings of length n with no substrings equal to 0001, 0110, or 0111.at n=26A164476
- Potential magic constants of 9 X 9 magic squares composed of consecutive primes.at n=16A191679
- Numbers with digital product = 10.at n=26A199990
- Composite numbers whose product of digits is 10.at n=23A201057
- Triangle of coefficients of polynomials u(n,x) jointly generated with A210859; see the Formula section.at n=49A210858
- Numbers k such that k + (sum of digits of k) and k + (product of digits of k) contain the same distinct digits of k.at n=6A248718
- Semiprimes such that sum of digits equals product of digits.at n=13A272436
- a(n) = a(n-1) + 3*a(n-2) -2*a(n-3) - 2*a(n-4), where a(0) = -2, a(1) = -2, a(2) = 2, a(3) = 1.at n=16A295854
- a(n) = Sum_{k=1..n} sigma_2(k) * floor(n/k).at n=28A356042
- a(n) = n! * Sum_{k=1..n} sigma_2(k)/(k * (n-k)!).at n=5A356600