6742
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10116
- Proper Divisor Sum (Aliquot Sum)
- 3374
- 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
- 3370
- Möbius Function
- 1
- Radical
- 6742
- 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
- 75
- 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
- a(n) = floor(n*(n-1)*(n-2)/4).at n=31A011886
- Numbers k such that the continued fraction for sqrt(k) has period 74.at n=16A020413
- a(n) = [ a(n-1)/a(1) + a(n-3)/a(3) + a(n-5)/a(5) + ... ], for n >= 3.at n=28A022865
- When squared gives number composed of digits {4,5,6}.at n=6A030177
- 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 82.at n=2A031580
- Numbers whose base-4 representation contains exactly four 1's and three 2's.at n=16A045108
- Numbers which have more different digits than their squares.at n=37A061277
- a(n) = 15*n^2 + 6*n + 1.at n=21A080861
- a(n) = round( (sqrt n)^(sqrt n) ).at n=27A094054
- a(n) = floor(sqrt(n)^sqrt(n)).at n=27A094092
- Numbers k such that sigma(k) plus the k-th prime is a triangular number.at n=25A115907
- Triangle P, read by rows, where column k of P^3 equals column 0 of P^(3k+3) such that column 0 of P^3 equals column 0 of P shift one row up, with P(0,0)=1.at n=31A136220
- Column 3 of triangle A136220; also equals column 0 of U^4 where U = A136228.at n=4A136224
- Numbers k such that k and k^2 use only the digits 2, 4, 5, 6 and 7.at n=30A137094
- a(n) = 3*A146085(n) - 2.at n=35A146091
- Number of binary strings of length n with no substrings equal to 0011 or 0101.at n=17A164406
- Number of nX5 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 2 neighbors with the same value.at n=4A164757
- Number of nX6 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 2 neighbors with the same value.at n=3A164758
- Triangle of coefficients of polynomials u(n,x) jointly generated with A207634; see the Formula section.at n=49A207633
- Consider the ordered Goldbach partitions of the even numbers m. Then a(n) is the least m which contains prime(n) such partitions composed of odd primes.at n=37A216047