3901
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
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4032
- Proper Divisor Sum (Aliquot Sum)
- 131
- 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
- 3772
- Möbius Function
- 1
- Radical
- 3901
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 144
- 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
- Expansion of 1/(1-x)^2/(1-x^2)/(1-x^4)/(1-x^10)/(1-x^20).at n=42A001307
- Centered 12-gonal numbers, or centered dodecagonal numbers: numbers of the form 6*k*(k-1) + 1.at n=25A003154
- Numbers that are the sum of 9 positive 6th powers.at n=44A003365
- Centered pentagonal numbers: (5n^2+5n+2)/2; crystal ball sequence for 3.3.3.4.4. planar net.at n=39A005891
- Hyperperfect numbers: k = m*(sigma(k) - k - 1) + 1 for some m > 1.at n=8A007592
- Least m such that if r and s in {1/1, 1/3, 1/6,..., 1/C(n+1,2)} satisfy r < s, then r < k/m < s for some integer k.at n=27A024826
- (d(n)-r(n))/5, where d = A008778 and r is the periodic sequence with fundamental period (0,3,1,0,1).at n=45A026053
- Square root of A030688.at n=38A030689
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 48 ones.at n=3A031816
- Numbers k such that 209*2^k+1 is prime.at n=13A032481
- Hyperperfect numbers: x such that x = 1 + k*(sigma(x)-x-1) for some k > 0.at n=11A034897
- Number of partitions of n with equal nonzero number of parts congruent to each of 0, 1 and 3 (mod 5).at n=52A035583
- Sums of 5 distinct powers of 5.at n=4A038477
- Smallest of three consecutive squarefree numbers k, k+1, k+2 of the form p*q where p and q are distinct primes.at n=40A039833
- Numbers whose base-4 representation contains exactly one 0 and four 3's.at n=34A045070
- First palindrome greater than n+2 in bases n+2 and n.at n=48A048269
- a(n) is the number of unlabeled forests of rooted trees with n nodes such that no two trees are identical.at n=11A052827
- a(n) = 2*n^2 + 9*n - 5.at n=41A056237
- Numbers k such that k, k+1 and k+2 are products of two primes.at n=42A056809
- Number of self-converse monoids (semigroups with identity) of order n.at n=7A058132