3721
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 3
- Divisor Sum
- 3783
- Proper Divisor Sum (Aliquot Sum)
- 62
- 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
- 3660
- Möbius Function
- 0
- Radical
- 61
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 1
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- yes
- 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
- yes
- Squarefree Number
- no
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Squares of primes.at n=17A001248
- Sum of squares of primes dividing n.at n=60A005063
- Sum of squares of odd primes dividing n.at n=60A005066
- Sum of squares of primes = 1 mod 3 dividing n.at n=60A005071
- Sum of squares of primes = 1 mod 4 dividing n.at n=60A005079
- Crystal ball sequence for D_4 lattice.at n=5A007204
- Number of partitions of n in which no part occurs just once.at n=46A007690
- Odd squares: a(n) = (2n+1)^2. Also centered octagonal numbers.at n=30A016754
- a(n) = (3*n+1)^2.at n=20A016778
- a(n) = (4*n + 1)^2.at n=15A016814
- a(n) = (5*n + 1)^2.at n=12A016862
- a(n) = (6*n + 1)^2.at n=10A016922
- a(n) = (7*n + 5)^2.at n=8A017042
- a(n) = (8*n + 5)^2.at n=7A017126
- a(n) = (9*n + 7)^2.at n=6A017246
- a(n) = (10*n + 1)^2.at n=6A017282
- a(n) = (11*n + 6)^2.at n=5A017462
- a(n) = (12*n + 1)^2.at n=5A017534
- Expansion of 1/(1-x^3-x^4-x^5).at n=34A017818
- Expansion of 1/(1 - x^4 - x^5 - x^6 - x^7).at n=38A017829