2931
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3912
- Proper Divisor Sum (Aliquot Sum)
- 981
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1952
- Möbius Function
- 1
- Radical
- 2931
- 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
- 35
- 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
- Number of trees of diameter 6.at n=9A000251
- a(n) = a(n-1) + 2*a(n-3).at n=15A003476
- Juxtapose pairs of primes (starting at 1).at n=5A007794
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 53.at n=12A031551
- Concatenation of n and n + 2 or {n,n+2}.at n=28A032607
- Coordination sequence T5 for Zeolite Code SFF.at n=36A038436
- Number of partitions satisfying cn(2,5) <= cn(0,5) + cn(1,5) + cn(4,5) and cn(3,5) <= cn(0,5) + cn(1,5) + cn(4,5).at n=27A039871
- Number of partitions satisfying 0 < cn(0,5) + cn(2,5) + cn(3,5).at n=27A039899
- Numbers n such that string 3,1 occurs in the base 10 representation of n but not of n-1.at n=32A044363
- Numbers n such that string 3,1 occurs in the base 10 representation of n but not of n+1.at n=32A044744
- Concatenate the n-th and (n+1)st prime.at n=9A045533
- Discriminants of imaginary quadratic fields with class number 14 (negated).at n=32A046011
- Number of horizontally convex n-ominoes in which the top row has at least 2 squares and the rightmost square in the top row is above the leftmost square in the second row.at n=9A049220
- Concatenate prevprime(n) and n.at n=28A049851
- Concatenate "n" and "nextprime(n)".at n=28A049852
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 22.at n=30A051987
- Number of vertically indecomposable distributive lattices on n nodes.at n=22A072361
- a(n) = n-th squarefree number beginning with n.at n=28A077687
- a(0)=1, then the fractional part of Pi*a(n) decreases monotonically to zero.at n=40A079043
- Sum of first n 4-almost primes.at n=25A086046