3998
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 6000
- Proper Divisor Sum (Aliquot Sum)
- 2002
- 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
- 1998
- Möbius Function
- 1
- Radical
- 3998
- 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
- 51
- 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
- yes
- Odd
- no
Appears in sequences
- From a counter moving problem.at n=15A004138
- Mian-Chowla sequence (a B_2 sequence): a(1) = 1; for n>1, a(n) = smallest number > a(n-1) such that the pairwise sums of elements are all distinct.at n=45A005282
- Coordination sequence T1 for Zeolite Code DOH.at n=39A008078
- Coordination sequence for MgCu2, Cu position.at n=16A009930
- Coordination sequence for MgZn2, Position Zn2.at n=16A009938
- Nine iterations of Reverse and Add are needed to reach a palindrome.at n=22A015990
- 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 62.at n=10A031560
- Decimal part of a(n)^(1/7) starts with n so that a(n) < a(n+1).at n=27A034072
- Trajectory of 3 under map n->7n+1 if n odd, n->n/2 if n even.at n=24A037101
- Coordination sequence T5 for Zeolite Code ESV.at n=42A038414
- Numbers whose base-5 representation contains exactly three 1's and two 4's.at n=27A045261
- Numbers which need nine 'Reverse and Add' steps to reach a palindrome.at n=22A065214
- Smallest even number with digit sum n.at n=28A069532
- Numbers k such that k^4 + 1, (k+2)^4 + 1 and (k+4)^4 + 1 are all primes.at n=3A073476
- Maximum number of regions into which the plane is divided by n triangles.at n=37A077588
- Spt function: total number of smallest parts (counted with multiplicity) in all partitions of n.at n=21A092269
- In binary representation: least number, k, which occurs n times in its factorial.at n=20A093826
- Indices of primes in sequence defined by A(0) = 67, A(n) = 10*A(n-1) - 33 for n > 0.at n=16A101526
- Least k such that 10^n + k - 1 is the first of a pair of twin primes.at n=47A103129
- Expansion of q^(-1) * f(-q^2, -q^5)^2 * f(-q^3, -q^4) / f(-q^1, -q^6)^3 in powers of q where f() is Ramanujan's two-variable theta function.at n=44A108481