3931
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 3932
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 3930
- Möbius Function
- -1
- Radical
- 3931
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 82
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 546
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Site percolation series for square lattice.at n=17A006731
- Coordination sequence T1 for Zeolite Code LTL.at n=46A008138
- Coordination sequence T7 for Zeolite Code MTW.at n=41A008202
- a(n) = floor( n*(n-1)*(n-2)/5 ).at n=28A011887
- Values of k at which the period of the continued fraction for sqrt(k) sets a new record.at n=37A013645
- Smallest nonempty set S containing prime divisors of 8k+3 for each k in S.at n=52A020617
- Primes that remain prime through 2 iterations of function f(x) = 9x + 2.at n=46A023265
- Primes that remain prime through 3 iterations of function f(x) = 9x + 2.at n=16A023296
- Primes that remain prime through 4 iterations of function f(x) = 9x + 2.at n=6A023324
- Primes that remain prime through 5 iterations of function f(x) = 9x + 2.at n=3A023352
- Index of 10^n within the sequence of the numbers of the form 2^i*10^j.at n=48A025740
- Sum{T(i,j)}, 0<=i<=n, 0<=j<=n, T given by A026692.at n=10A026701
- a(n) = T(n,m) + T(n,m+1) + ... + T(n,n), m=[ (n+1)/2 ], T given by A026758.at n=12A026880
- 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 61.at n=19A031559
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 54 ones.at n=0A031822
- Lucky numbers with size of gaps equal to 16 (upper terms).at n=14A031899
- Lower prime of a difference of 12 between consecutive primes.at n=38A031930
- Number of partitions in parts not of the form 11k, 11k+3 or 11k-3. Also number of partitions with at most 2 parts of size 1 and differences between parts at distance 4 are greater than 1.at n=34A035946
- Discriminants of imaginary quadratic fields with class number 11 (negated).at n=20A046008
- Number of partitions of n with equal number of parts congruent to each of 0, 2 and 3 (mod 4).at n=49A046768