3961
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4212
- Proper Divisor Sum (Aliquot Sum)
- 251
- 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
- 3712
- Möbius Function
- 1
- Radical
- 3961
- 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
- 51
- 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
- 9-gonal (or enneagonal or nonagonal) numbers: a(n) = n*(7*n-5)/2.at n=34A001106
- Centered square numbers: a(n) = 2*n*(n+1)+1. Sums of two consecutive squares. Also, consider all Pythagorean triples (X, Y, Z=Y+1) ordered by increasing Z; then sequence gives Z values.at n=44A001844
- Salié numbers.at n=5A005647
- Smallest odd number expressible in at least n ways as p+2*m^2 where p is 1 or a prime and m >= 0.at n=30A007697
- Coordination sequence T10 for Zeolite Code MFI.at n=40A008162
- Coordination sequence T1 for Zeolite Code PAU.at n=46A008219
- Start with 1, apply 1->12, 21->21, 22->21, 2->2 (for final 2); a(n) = length of n-th term.at n=25A013950
- Quadruples of different integers from [ 1,n ] with no common factors between triples.at n=20A015625
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite BEA = Beta Na7[Al7Si57O128] starting with a T5 atom.at n=11A019071
- Pseudoprimes to base 89.at n=41A020217
- Strong pseudoprimes to base 89.at n=8A020315
- Numbers k such that the continued fraction for sqrt(k) has period 43.at n=9A020382
- Fibonacci sequence beginning 0, 17.at n=13A022351
- Least m such that if r and s in {1/2, 1/5, 1/8,..., 1/(3n-1)}, satisfy r < s, then r < k/m < s for some integer k.at n=41A024823
- Number of partitions of n that do not contain 2 as a part.at n=34A027336
- Odd 9-gonal (or enneagonal) numbers.at n=17A028991
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 6.at n=13A031419
- "BGJ" (reversible, element, labeled) transform of 1,0,1,0... (odds).at n=11A032050
- Coordination sequence T3 for Zeolite Code STF.at n=42A038442
- Sizes of successive balls in D_4 lattice.at n=20A046949