11990
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 23760
- Proper Divisor Sum (Aliquot Sum)
- 11770
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4320
- Möbius Function
- 1
- Radical
- 11990
- Omega Function (Ω)
- 4
- 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
- yes
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 81
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = (3*n+1)*(3*n+2).at n=36A001504
- a(n) = n*(3*n^2 - 1)/2.at n=20A004188
- Coordination sequence for Cr3Si, Cr position.at n=28A009928
- Product of a prime and the following number.at n=28A036690
- Squarefree numbers k with largest prime factor = floor(sqrt(k)).at n=17A071311
- Numbers n for which there are exactly nine k such that n = k + reverse(k).at n=30A072433
- Deficient oblong numbers.at n=17A077804
- Numbers k such that the largest prime power factor of k equals floor(sqrt(k)).at n=45A081807
- Number of doubletons in all partitions of n. By a doubleton in a partition we mean an occurrence of a part exactly twice (the partition [4,(3,3),2,2,2,(1,1)] has two doubletons, shown between parentheses).at n=35A116646
- Number of integer-sided pentagons having perimeter n.at n=46A124285
- 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, 0, 0), (0, -1, 0), (0, 0, -1), (0, 0, 1), (1, 1, 1)}.at n=7A150832
- a(n) = (4*n+1)*(4*n+2) = (4*n+2)!/(4*n)!.at n=27A157870
- Numerator of Euler(n,11).at n=4A157886
- Number of lines through at least 2 points of a 6 X n grid of points.at n=38A160846
- Partial sums of A048890.at n=13A172973
- Row sums of an irregular triangle read by rows in which row n lists the next A026741(n+1) natural numbers A000027.at n=38A195309
- Number of n X 3 0..2 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.at n=5A224257
- T(n,k) = number of n X k 0..2 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.at n=33A224262
- Number of 6 X n 0..2 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.at n=2A224266
- Squarefree oblong numbers.at n=37A229882