12787
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13480
- Proper Divisor Sum (Aliquot Sum)
- 693
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12096
- Möbius Function
- 1
- Radical
- 12787
- 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
- 169
- 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
- a(n) = 10000*log_10(n) rounded down.at n=18A004228
- Number of partitions of n into parts not of the form 13k, 13k+2 or 13k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 5 are greater than 1.at n=42A035950
- Expansion of -(20*x^12 + 184*x^11 + 121*x^10 - 915*x^9 -1 524*x^8 - 132*x^7 + 1068*x^6 + 581*x^5 - 71*x^4 - 112*x^3 - 14*x^2 + 5*x +1) / ((3*x +1) * (16*x^12 + 140*x^11 + 2*x^10 - 968*x^9 - 830*x^8 + 946*x^7 + 982*x^6 - 239*x^5 - 351*x^4 - 5*x^3 + 39*x^2 + 3*x -1)).at n=5A120469
- Number of n X n {0,-1,1}-matrices A such that permanent( |A| ) = | det A |, where |A| is obtained from A by taking the absolute value of each entry.at n=3A145675
- Number of planar triangular n X n X n nonnegative integer grids with mirror symmetry about one altitude with every similarly oriented 5 X 5 X 5 subtriangle summing to 12.at n=13A154086
- G.f.: q-sinh(x) evaluated at q=-x.at n=38A198202
- Floor(M(g(n-1)+1,..,g(n))), where M = harmonic mean and g(n) = n(n + 1)(n + 2)/6.at n=41A227016
- a(n) = A002703(n)/2.at n=17A262567
- The number of partitions of n which represent Chomp positions with Sprague-Grundy value 9.at n=54A284782
- Numbers k such that k!6 - 12 is prime, where k!6 is the sextuple factorial number (A085158).at n=22A289688
- Positions of new record minima A372935 in A071961.at n=15A372936