3621
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 5184
- Proper Divisor Sum (Aliquot Sum)
- 1563
- 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
- 2240
- Möbius Function
- -1
- Radical
- 3621
- 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
- 69
- 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
- Coordination sequence T8 for Zeolite Code EUO.at n=37A008103
- Expansion of 1/(1-x^3-x^4-x^5-x^6-x^7).at n=28A017820
- Sum of gcd(x, y) for 1 <= x, y <= n.at n=37A018806
- Numbers k such that the continued fraction for sqrt(k) has period 38.at n=41A020377
- a(n) = n*(25*n + 1)/2.at n=17A022283
- Convolution of (F(2), F(3), F(4), ...) and A000201.at n=12A023653
- a(n) = number of partitions of n into an odd number of parts, the least being 2; also a(n+2) = number of partitions of n into an even number of parts, each >=2.at n=43A027188
- Number of matroids: column 6 of A034328.at n=11A034336
- Positive numbers having the same set of digits in base 7 and base 10.at n=23A037440
- Numerators of continued fraction convergents to sqrt(88).at n=6A041156
- Denominators of continued fraction convergents to sqrt(157).at n=11A041289
- Numerators of continued fraction convergents to sqrt(352).at n=4A041666
- Denominators of continued fraction convergents to sqrt(628).at n=7A042205
- a(1) = 7; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=38A046257
- Distinct odd numbers in the numerators of the 1/5-Pascal triangle (by row).at n=41A046624
- Distinct odd numbers in writing first numerator and then denominator of each element to the right of the central elements of the 1/5-Pascal triangle (by row).at n=42A046628
- Discriminants of real quadratic number fields K with class number 2 such that the Hilbert class field of K is K(sqrt(17)).at n=37A052479
- Positive numbers whose product of digits is three times their sum.at n=43A062035
- Harmonic mean of digits is 2.at n=40A062180
- Canonically 2-indecomposable posets with n antichains.at n=24A072407