3685
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4896
- Proper Divisor Sum (Aliquot Sum)
- 1211
- 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
- 2640
- Möbius Function
- -1
- Radical
- 3685
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 131
- 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
- no
- Odd
- yes
Appears in sequences
- Alkane (or paraffin) numbers l(7,n).at n=18A005994
- Numbers k that divide s(k), where s(1)=1, s(j)=15*s(j-1)+j.at n=28A014865
- a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n+1-k), where k = [ (n+1)/2 ], s = A001950 (upper Wythoff sequence).at n=17A024689
- s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A001950 (upper Wythoff sequence).at n=16A025122
- Lucky numbers with size of gaps equal to 10 (upper terms).at n=40A031893
- Number of partitions satisfying cn(0,5) <= cn(1,5) + cn(4,5) + cn(2,5) + cn(3,5).at n=27A039849
- Numbers k such that the string 4,4 occurs in the base 9 representation of k but not of k-1.at n=45A044291
- Obtainable by applying +, * and exponentiation to its own digits.at n=16A046469
- Partial sums of A007584.at n=9A051740
- Numbers m such that there are precisely 3 groups of order m.at n=17A055561
- a(n) is the least k in A002977 with a gap of n. Also n + a(n) is the least k in A007448 which is repeated n times.at n=25A058361
- a(n) = (n^3 + 5*n + 18)/6.at n=30A060163
- Numerator of 1/36 - 1/n^2.at n=60A061045
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 100 ).at n=23A063373
- Records for the number of integers k such that k is not of the form m + reverse(m) for any m and for some n A067030(n) occurs in the 'Reverse and Add' trajectory of k (cf. A067284).at n=43A067288
- a(n) = n*(n+1)*(2*n^2+1)/6.at n=10A071238
- "Orderly" Friedman numbers (or "good" or "nice" Friedman numbers): Friedman numbers (A036057) where the construction digits are used in the proper order.at n=9A080035
- Numerators of triangular array: T(n,1)=T(n,n)=1/n and T(n,k)=T(n-1,k-1)+T(n-1,k), 1<k<n.at n=57A080044
- Least n such that n consecutive values in A080378 equals 2; i.e., exactly n differences between consecutive primes give residues 2 when divided by 4.at n=9A080379
- Numbers n for which the first difference sequence of A054040 decreases.at n=37A082915