3131
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3264
- Proper Divisor Sum (Aliquot Sum)
- 133
- 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
- 3000
- Möbius Function
- 1
- Radical
- 3131
- 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
- 110
- 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 partitions into non-integral powers.at n=25A000327
- Molien series for Conway group Con.0.at n=34A008925
- If a, b in sequence, so is ab+5.at n=37A009304
- Coordination sequence T2 for Zeolite Code VET.at n=34A009903
- Pseudoprimes to base 95.at n=16A020223
- Strong pseudoprimes to base 95.at n=2A020321
- Doublets: base-10 representation is the juxtaposition of two identical strings.at n=30A020338
- a(n) = sum of the numbers between the two n's in A026346.at n=36A026349
- Square of the lower triangular normalized Eulerian number matrix.at n=10A027537
- First column of A027537.at n=4A027546
- Numbers having only digits 1 and 3 in their decimal representation.at n=24A032917
- Sums of distinct powers of 5.at n=35A033042
- Coordination sequence T2 for Zeolite Code SBE.at n=45A033605
- Numbers with multiplicative digital root value 9.at n=17A034056
- Nonprime; becomes prime if any digit is deleted (zeros not allowed in the number).at n=40A034304
- Positive numbers having the same set of digits in base 2 and base 5.at n=31A037410
- Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 3,1.at n=3A037589
- Sums of 3 distinct powers of 5.at n=10A038475
- Number of partitions satisfying cn(1,5) + cn(4,5) <= cn(0,5) + cn(2,5) and cn(1,5) + cn(4,5) <= cn(0,5) + cn(3,5).at n=34A039864
- Denominators of continued fraction convergents to sqrt(569).at n=8A042091