3215
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3864
- Proper Divisor Sum (Aliquot Sum)
- 649
- 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
- 2568
- Möbius Function
- 1
- Radical
- 3215
- 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
- 167
- 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
- Coordination sequence T1 for Zeolite Code BRE.at n=37A008058
- Coordination sequence T1 for Zeolite Code CON.at n=40A009868
- Expansion of 1/((1-x)(1-8x)(1-10x)).at n=3A016257
- Coordination sequence T6 for Zeolite Code TER.at n=38A016438
- 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 11.at n=28A031509
- Decimal part of n-th root of a(n) starts with digit 4.at n=22A034081
- Numerators of continued fraction convergents to sqrt(824).at n=6A042590
- Numbers whose base-7 representation contains exactly three 2's.at n=37A043403
- Numbers k such that the string 6,2 occurs in the base 9 representation of k but not of k-1.at n=43A044307
- Numbers n such that string 1,5 occurs in the base 10 representation of n but not of n-1.at n=36A044347
- Numbers n such that string 1,5 occurs in the base 10 representation of n but not of n+1.at n=36A044728
- Numbers whose base-4 representation contains exactly two 0's and three 3's.at n=35A045074
- Numbers whose base-5 representation contains exactly three 0's and one 1.at n=44A045170
- Numbers whose base-5 representation contains exactly three 0's and two 3's.at n=6A045201
- Numbers that in base 2 need twelve 'Reverse and Add' steps to reach a palindrome.at n=15A066133
- Square roots of squares in A068176.at n=5A091875
- Composite de Polignac numbers (A006285).at n=30A098237
- Odd numbers n such that there exists a solution to lcm(s,z-s) = n, lcm(t,z-t) = n-2 and 0 < s+t < z < n.at n=15A108157
- Sum of the squares of the first n nonsquarefree numbers (A013929).at n=10A111732
- Positive integers i for which A112049(i) == 7.at n=4A112067