8042
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12066
- Proper Divisor Sum (Aliquot Sum)
- 4024
- 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
- 4020
- Möbius Function
- 1
- Radical
- 8042
- 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
- 70
- 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
- Numbers k such that the continued fraction for sqrt(k) has period 23.at n=33A020362
- Length of n-th term of A022482.at n=29A022483
- Convolution of the lower and upper Wythoff sequences (A000201 and A001950).at n=21A023664
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Fibonacci numbers), t = (1, p(1), p(2), ...).at n=20A024460
- Number of proper factorizations of p1^n*p2^7, where p1 and p2 are distinct primes.at n=9A031130
- T(n,n-2), array T as in A047150.at n=7A047154
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 23.at n=14A051988
- Number of asymmetric trees with a forbidden limb of length 3.at n=23A052326
- Expansion of g.f.: (1 + x)/(1 - 3*x - 2*x^2).at n=7A055099
- a(n) = Sum_{k=1..n} phi(k)^2.at n=37A057434
- Sum of product of divisors of n and sum of divisors of n.at n=19A076720
- Number of partitions of n such that the least part occurs exactly twice.at n=41A096373
- Triangle read by rows T(n,k) = the number of Dyck paths of semilength n with k UUDDU's, 0<=k<=[(n-1)/2].at n=33A114848
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (-1, 1, -1), (1, -1, 0), (1, 1, 0)}.at n=8A149153
- Numbers that have an "a" in the middle of their names in Spanish.at n=34A160775
- Least number k having n representations as the sum of the minimal number of cubes A002376(k).at n=18A163490
- Conjecturally, even numbers n such that every even number greater than n has more decompositions as the sum of two primes.at n=44A174327
- Number of nX7 binary matrices with no 2X2 circuit having pattern 0101 in any orientation.at n=1A181242
- T(n,k) = Number of n X k binary matrices with no 2 X 2 circuit having pattern 0101 in any orientation.at n=34A181245
- T(n,k) = Number of n X k binary matrices with no 2 X 2 circuit having pattern 0101 in any orientation.at n=29A181245