3949
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4320
- Proper Divisor Sum (Aliquot Sum)
- 371
- 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
- 3580
- Möbius Function
- 1
- Radical
- 3949
- 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
- 38
- 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 T2 for Zeolite Code -ROG.at n=47A009860
- Coordination sequence T3 for Zeolite Code ZON.at n=44A009921
- Number of squares on infinite chessboard at <= n knight's moves from a fixed square.at n=17A018836
- Numbers k such that Fibonacci(k) == 89 (mod k).at n=43A023182
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 56 ones.at n=2A031824
- Number of partitions of n with equal nonzero number of parts congruent to each of 0, 2 and 4 (mod 5).at n=48A035586
- Numbers having three 5's in base 8.at n=27A043443
- Numbers whose base-5 representation contains exactly three 1's and two 4's.at n=20A045261
- a(1) = 4; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=34A046254
- A Diaconis-Mosteller approximation to the Birthday problem function.at n=21A050255
- 19-gonal (or enneadecagonal) numbers: n(17n-15)/2.at n=22A051871
- Triangle of number of falls in set partitions of n.at n=37A056859
- Numbers k such that 3*2^k + 5 is prime.at n=41A057913
- Semiprimes p1*p2 such that p2>p1 and p2 mod p1 = 7.at n=19A064905
- Trisection of A007294.at n=28A073471
- Numbers n such that the sum of the anti-divisors of n = phi(n).at n=4A074713
- a(n+1) = a(n)+greatest prime divisor of a(n-1).at n=35A078695
- a(n) = (1/12)*(n+1)*(n^3+19*n^2+118*n+228).at n=11A092327
- Pythagorean years: a Pythagorean year is one whose digits partition into two disjoint sets such that, considering digital sums, the Pythagorean relation 5^2=4^2 + 3^2 is evinced.at n=41A101039
- Numbers k such that 13k = 6j^2 + 6j + 1.at n=14A106390