12031
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 7
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12312
- Proper Divisor Sum (Aliquot Sum)
- 281
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11752
- Möbius Function
- 1
- Radical
- 12031
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 99
- 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
- McKay-Thompson series of class 8A for Monster.at n=8A007265
- Numbers k that divide the (left) concatenation of all numbers <= k written in base 23 (most significant digit on left).at n=21A029492
- Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,2,0,3.at n=4A037694
- Sums of 12 distinct powers of 2.at n=16A038463
- McKay-Thompson series of class 8A for Monster.at n=8A045490
- Concerning the popular MMORPG "Runescape" by JAGeX corporation, this sequence gives the number of experience points needed for a given level in a skill.at n=28A111078
- Number of bipartite outerplanar graphs on n unlabeled nodes.at n=11A111759
- a(n) = 12 + floor((1 + Sum_{j=1..n-1} a(j))/4).at n=31A120169
- a(1)=a(2)=1; thereafter, a(n+1) = a(n) + a(n-1) + 1 if n is a multiple of 5, otherwise a(n+1) = a(n) + a(n-1).at n=20A124502
- McKay-Thompson series of class 8A for the Monster group with a(0) = 8.at n=8A131123
- McKay-Thompson series of class 8A for the Monster group with a(0) = 2.at n=8A134785
- A sequence of asymptotic density zeta(9) - 1, where zeta is the Riemann zeta function.at n=23A143035
- Composite numbers generated by the Euler polynomial x^2 + x + 41.at n=16A145292
- 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, -1, -1), (-1, -1, 0), (0, 0, -1), (0, 1, 0), (1, 0, 1)}.at n=8A150000
- a(n) = Sum_{i=1..Fibonacci(n)} sigma_0(i) where sigma_0(n) is A000005(n).at n=16A158568
- Triangle of coefficients of polynomials u(n,x) jointly generated with A207636; see the Formula section.at n=48A207635
- Semiprimes generated by the Euler polynomial x^2 + x + 41.at n=16A228183
- Decimal value of the bitmap of active segments in 7-segment display of the number n, variant 1: bits 0-6 refer to segments from top to bottom, left to right.at n=28A234691
- Array read by antidiagonals: T(n,k) = number of possible positions in standard Connect Four play on a board of height n and width k (n>=1, k>=1).at n=18A235610
- List of numbers n whose base-3 expansion contains only the digits 1 and 2 and whose base-4 expansion contains only the digits 2 and 3.at n=11A262963