5678
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9072
- Proper Divisor Sum (Aliquot Sum)
- 3394
- 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
- 2656
- Möbius Function
- -1
- Radical
- 5678
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 129
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Concatenate the natural numbers, then partition into minimal strings so that each term divides the next.at n=3A002782
- Coordination sequence T4 for Zeolite Code TON.at n=47A008244
- Number of partitions of n^2 into distinct squares.at n=38A030273
- 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 74.at n=14A031572
- Denominators of continued fraction convergents to sqrt(386).at n=11A041733
- Triangle of rooted identity trees with n nodes and k leaves.at n=61A055327
- Number of rooted identity trees with n nodes and 5 leaves.at n=6A055330
- Numbers n such that x^n + x + 2 is irreducible over GF(3).at n=13A058059
- Numbers in which each digit is the (immediate) successor of the previous one (if it exists) and 0 is considered the successor of 9.at n=32A059043
- Row sums of triangle in A074829.at n=11A074878
- Maximum number of regions into which the plane is divided by n triangles.at n=44A077588
- In the following triangle the n-th row contains n n-digit (or (n-1)-digit) numbers whose concatenation (with a 0 prefixed for (n-1)-digit numbers) gives a substring of the cyclic concatenation of 1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,...: 1; 12 34; 123 456 789; 1234 5678 9012 3456; 12345 67890 12345 67890 12345; ... Sequence contains the triangle by rows.at n=7A078194
- Left truncatable 3-almost primes, in which repeatedly deleting the leftmost digit gives a 3-almost prime at every step until a single-digit 3-almost prime remains.at n=38A085248
- Let S = 12345678901234567890123456..., the cyclic concatenation of digits; partition this string into distinct squarefree numbers. To avoid leading zeros, no member may end with the digit 9.at n=22A085944
- a(n+1) is the least positive integer k such that (1) k is a one-digit number or the concatenation of two or more consecutive numbers; (2) |k-a(n)| is prime; (3) k is not already in the sequence; and (4) |k-a(n)| is not the absolute difference of two previous consecutive members of the sequence.at n=36A090910
- Natural numbers written out with their digits grouped in sets of four (leading zeros omitted).at n=1A091332
- Smallest available integer which fits into the repeating pattern 0123456789.at n=26A098755
- G.f. satisfies: A(x) = 1/(1 + x*A(x^4)) and also the continued fraction: 1 + x*A(x^5) = [1; 1/x, 1/x^4, 1/x^16, 1/x^64, ..., 1/x^(4^(n-1)), ...].at n=53A101914
- Concatenation of 3 or more numbers in arithmetic progression with positive common difference.at n=37A119426
- E.g.f.: exp(-2*(exp(exp(-x/(2*x-1))-1)-1)/(-2+exp(exp(-x/(2*x-1))-1))).at n=4A124211